How can I compress a string with pure vfp code?

What I want to achieve is to reduce the size of files that I'm sending inside a XML file.

cFile = FILETOSTR('c:\somefile.dat') && 21k in size
cFileB64 = STRCONV(cFileB64,'c:\asistencia.b64',0) && 28k in size

I know there are some algorithms for string compression with is good for base64
I found one in http://www.pbcrypto.com/view.php?algorithm=stringcompr

Any ideas?
Thanks