Fedora

Hi,
I need some help.

My task is, to write a "one-line" command, which must use ls and awk.
Task: Write a command-line, which should rename all files in dir from form "value1.dok" to "value2.doc". And value2=value1+1.

For example:

Code:

ls | awk -F: '{print "mv "$0" "$1+1".doc"}' | sh

But this doesn't work with a filename with characters. Therefore i tested this:

Code:

ls | awk -F: '{print "mv "$0" value"substr($1 ,6)+1".doc"}' | sh

This worked, but my taskprogram say "wrong" and want see a other command (perhaps with different string?)
So i tested it with regular expressions, but my console say always "syntax error":

Code:

ls | awk -F: '{print "mv "$0" "${1%[!0-9]*}""${1%[0-9]*}+1".doc"}' | sh

I havent any idea how i could it bring to work in one line...

Can someone perhaps help me?
And sorry for my very bad english