You can use the tyActor property window to assign a simulation group to the bone objects of your choosing in the scene. The assigned properties from that window will transfer to the corresponding actor rig particles.
From there, you can use a Property Test to test for that group on the corresponding rig particles. and send the matching particle to another event, where you can use a PhysX Bind operator (with "world" checked) to pin it in space.
From there, you can use a Property Test to test for that group on the corresponding rig particles. and send the matching particle to another event, where you can use a PhysX Bind operator (with "world" checked) to pin it in space.