custom dll's in userefi directory and Mathcad14/Win7-64b

Hi,

I have a dll I have used extensively over the years and it works in Win XP with Mcad14, but for some reason now I am on Win7-64b the functions in my dll are no longer accessable in mathcad.

How do I get user dll's to work in Mathcad14 in Win7/64b?

I have attached the dll in question.

Thanks.