Runtime Code Compiler

Question

Right now I have an application which is sort of like Excel, but is more powerful in the fact that I can run C# code within each cell. A cell has a formula, which is any expression, and a function, which is the C# code. I can do any type of loop or logical statement in the function on a variable(s) and reference those in the formula.

Example:

Function
-----------------

int value = 0;
for( int x = 0; x < 10; x++ )
{
    value ++ x;
}

int value = 0; for( int x = 0; x < 10; x++ ) { value ++ x; }

Formula = value * 10
Result = 90


Right now I am doing this through CodeDom, which is a little slower than I would like. Is there another alternative I could do which is much faster but still gives me the power of being able to do what I can here?