Pseudocode for constant time modular exponentiation
No.  If you don't have a strong math background, implementing RSA yourself is a  bad idea (and perhaps even if you do).  There are many ways to go wrong, which can open up subtle security weaknesses.

Instead, you should use a well-vetted RSA implementation from a standard crypto library, and a well-vetted protocol -- or hire a cryptographer who does understand the mathematics, if you don't think you can trust any existing implementation or need help selecting one that is suitable.