$ cat script.pl                                                                                                                                                                                                                              
use warnings;                                                                                                                                                                                                                                
use strict;                                                                                                                                                                                                                                  
                                                                                                                                                                                                                                             
die qq[Usage: perl $0 <infile> \n] unless @ARGV == 1;                                                                                                                                                                                        
                                                                                                                                                                                                                                             
my $displacement = 1;                                                                                                                                                                                                                        
                                                                                                                                                                                                                                             
printf qq[%s\t\t%s\t\t%s\n], qw[Field Displacement Length];                                                                                                                                                                                  
while ( <> ) {                                                                                                                                                                                                                               
        my @f = split /[:,]/, $_;                                                                                                                                                                                                            
        next unless @f >= 2;                                                                                                                                                                                                                 
        if ( $f[0] =~ m/\D/ && $f[1] =~ m/\A\d+\Z/ ) {                                                                                                                                                                                       
                printf qq[%s\t\t%s\t\t%d\n], $f[0], $displacement, $f[1];                                                                                                                                                                    
                $displacement += $f[1];                                                                                                                                                                                                      
        }                                                                                                                                                                                                                                    
}                                                                                                                                                                                                                                            
                                                                                                                                                                                                                                             
$ perl script.pl infile
Field           Displacement            Length                                                                                                                                                                                               
NAME            1               10                                                                                                                                                                                                           
ACCOUNT NUM             11              15                                                                                                                                                                                                   
DATE            26              8                                                                                                                                                                                                            
$