Very lazy way :)

I did it this way (and I an NOT a JavaScript programmer): 1. JavaScript code:

class JsMath
{
static function Eval(expression: String): double
{
return eval(expression);
};
}

2. Compile:

C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\jsc.exe /t:library jsMath.js

3. Use in C#:

    private static double ExpressionValue(string expr)
    {
        return JsMath.Eval(expr);
    }

OWL was the coolest framework way ahead of MFC... I miss it... :)