No offense, but this is kind of retarded. Code takes up space. Whether it's in the form of a pre-written, tested and robust module or in the form of proprietary code that you write/re-invent specifically for this project, it's going to take up disk space. I'll leave it up to you and your admins to determine which solution takes less time to code and support.
Granted, in this case you can get by with a small amount of code, I think it's rather silly to deny the installation of modules because of disk space restrictions. Perl code doesn't take up a lot of space anyway, and disk space is cheap.