Compressing a file's name string

I was working with files where each name records a lot of information about what is in its respective file and wanted to compress it a little bit. So I wanted to change it's 'base'.

And I noticed that BaseForm[] only works with bases from 2 to 36, and besides it does not work with arbitrary representations, like if you base 3 was using only the symbols, "y","t", and "x".

So I wrote a simple program and want to post it here for others to use freely or improve on if they feel like it.