Short String/integer compression

Question

Hey,

I need to compress relatively short strings(or integer/long) in vb.net, i've been told base64 is the direction to head in, but simply using convert.tobase64string() on a string of my length just makes it longer

the strings i will be using will always be of the same length and type, just different numbers, for example: "1406891123456777"

any level of compression is appreciated

Thanks,

Howard