Using fix move, lineforce, and planeforce 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, or if there is any other possible solution, or I need to change something to make the fixes compatible with dynamic group?

Thanks in advance,

PS. I asked this question a few days ago (, but because I didn’t receive any responses, I decided to send it once more.