I know you said this was a last resort, but you also mentioned it was urgent and I thought I'd help where I could. I don't know a Perl solution to change the line endings, but I use a freeware program called ToX (on Simtel) to convert line endings in Windows. You can select all of your text files in a windows directory and convert the line endings with a right-click.

I hope you don't need to resort to this, but in case you do, I hope it helps.