$
$ cat out_position.txt
Input Variant   Errors  Chromosomal Variant     Coding Variant(s)
NM_004004.5:c.283G>C            NC_000013.10:g.20763438C>G      NM_004004.5:c.283G>C    XM_005266354.1:c.283G>C XM_005266355.1:c.283G>C XM_005266356.1:c.283G>C
NM_004004.5:c.79G>C             NC_000013.10:g.20763642C>G      NM_004004.5:c.79G>C     XM_005266354.1:c.79G>C  XM_005266355.1:c.79G>C  XM_005266356.1:c.79G>C
NM_004004.5:c.35delG            NC_000013.10:g.20763686delC     NM_004004.5:c.35delG    XM_005266354.1:c.35delG XM_005266355.1:c.35delG XM_005266356.1:c.35delG
$
$
$ # Method 1 : Using a non-capturing grouping in Perl regular expression
$ perl -ne 'next if $. == 1;
            while (/\t*NC_(\d+)\.\S+g\.(\d+)(?:del)*([A-Z])>*([A-Z]*)/g) {
                printf ("%d\t%d\t%d\t%s\t%s\n", $1, $2, $2, $3, $4 || "-");
            }
           ' out_position.txt
13      20763438        20763438        C       G
13      20763642        20763642        C       G
13      20763686        20763686        C       -
$
$
$ # Method 2 : Using more elaborate but plain-vanilla regular expressions
$ perl -ne 'next if $. == 1;
            while (/\t*NC_(\d+)\.\S+g\.(\d+)(\S+[A-Z])/g) {
                ($num1, $num2, $common) = ($1, $2, $3);
                if ($common =~ /([A-Z])>([A-Z])/) {
                    ($ch1, $ch2) = ($1, $2)
                } elsif ($common =~ /del([A-Z])/) {
                    ($ch1, $ch2) = ($1, "-")
                }
                printf ("%d\t%d\t%d\t%s\t%s\n", $num1, $num2, $num2, $ch1, $ch2);
                map {undef} ($num1, $num2, $common, $ch1, $ch2);
            }
           ' out_position.txt
13      20763438        20763438        C       G
13      20763642        20763642        C       G
13      20763686        20763686        C       -
$
$