Writing software that uses Mathcad for back-end maths

I've been asked to quote to create commercial software that implements a mathematical solution on behalf of a client. I'm trying to decide if it is more cost effective for the client to have us write code to implement the maths, or to use Mathcad and to simply interface with it, from our code. Our code will be written in C# ASP.net Two Questions: 1) Is it possible to use MathCad in this way? 2) Is there any documentation about it that I can read prior to making a recommendation to my client? TIA Mike