how to call the displacement of a point in matlab function

Hi

I want to add a load by implementing such a function whose dependent variable is the displacement of a point(or the cross section of a beam) at a certain coordinate position. It is a time-dependent research, so the point load application position and the position of the called displacement are all moving.

It can be understood that the displacement of the previous time step will affect the load I applied.

I understand how to add a moving load, but how to call the displacement of a point in a spatial position as a function's dependent variable is a problem.

Thank you!! Liuchong