How to evaluate field data in specific point

Hello everyone,

I want to simulate particle-particle magnetic interaction in particle tracing.

I wrote down an equation for calculation of interaction force. I need to know other points magnetic field to use it in force equation.

I tried following phrase but it's not working...:)

model.input.H1(dest(qx),dest(qy))...

As I know 'model.input.H1' gives the field magnitude of (qx,qy)'s first element data

what about other points?

Thank you for attention and helpful suggestions,

Navid