Indesign and WordPress

We designed a registration form in the Adobe In-Design program with an formula for number of attendees x cost per head and an email link back to our our administration.

We have successfully uploaded the Conference Registration Form to our website, however, neither of the formulas work on our new wordpress website.

I have contacted our website developer company, who have not been able to help solve the problem.

Does anyone have any ideas? Is it that In-design is not compatible with wordpress? Any recommendations of a safe and secure plugin which would not make our site vulnerable for this us to redevelop the form?

Regards