Convert file to Comma-Delimited format

I’m looking for a way to convert a file to a comma delimited format *without* user intervention. I have a script that downloads a file from an AS/400 to a PC.

The problem is the file is delimited by spaces, and I need it delimited by commas (customer requirement). It’s a flat file with about 12-15 fields. The only spaces in the file are delimiters. Any way to convert it using a script/program/macro?

Thank you.