I have a RSA signature S (128 byte integer )
and modulus n (also 128 byte integer)

I need to calculate

( S**3 ) MOD n

All I need is to perform exponent ( S**3 ) and MOD operation on
128 byte integers.

Is there any large integer class callable from FoxPro which can calculate this ?

I looked also _cypt.vcx foundation class and into Windows Crypto API but
havent found any function which does this.

Any idea ?