Convert string into a number

[Geoffrey Brier]

Hello everyone ^^
I would like to know if it was possible to convert a string into a sequence of numbers ONLY using mathematical functions? If it's the case, could you show me some examples?
For instance :
query : select operation('abc')
result : 010203 (it's not the real numbers, just an example)

I have tried conv(hex('string'),16,10) but it seems it causes an overflow with long strings, so it does not work properly ...

Another question, is there any way to divide a string only using mathematical functions?

Thanks in advance,
Geoffrey