Yes, the people who frequent the monastery know Perl and have ESP as well. ;-)

OK, taking a great leap, here's what I would suggest:

• Get and install the Text::CSV module to read in the file. If you attempt to write your own csv-separator you will probably not handle embedded commas and strings correctly. Also, merlyn, who has more ESP than others, will find you and smite you heavily for re-inventing wheels.
• Use printf with fixed sizes to output records. That is, every specifier in your format should be preceded with a length.

Your basic algorithm then will be to open both files, then enter a loop where you read a line into an array, then write it out with fixed sizes.

To mis-quote Tom Christiansen: this reply may be somewhat sub-serious, but when you ask a vague question, you should expect a bit of whimsy.

HTH