I want to simulate Langevin dynamics of a sphere. But I want to apply a variable force along the z-direction. Actually, I have a set of force values (10,000 values) and I want to vary that force values in each time step of the simulation. For that, I am using `` setforce 0 0 v_force’’ where v_force is the variable. I am trying to use 'next ’ command for the variable v_force. But for a few values, it is possible to write in the script. But I have 10,000 values written in a different text file. I got stuck. Can you please help.