Error in using some fixes with dynamic group

Dear all,

I want to limit the movements of a dynamic group to a specific direction. To do so, I was thinking of using “move”, and either “lineforce” or “planeforce” fixes, together; however, none of these fixes allow the use of dynamic group.

I’m afraid if I’m missing something to make the fixes compatible with dynamic group, or if there is any other possible solution?

Thanks in advance,
Soheil