Problem related to Vdload subroutine

[aquib_sid]

I am trying to write a vdload subroutine to simulate an inflation model for an inflatable membrane structure. For that I need to apply pressure at various nodes/points, which also varies with respect to time. In the manual it is said that, to pick the nodes/points in Vdload subroutine, one can use nBlock parameter. But the problem is that nBlock does not pick one node/point at a time, rather it picks a set of nodes/points. So I am unable to identify the node at hand to apply load.
Also i can not use curCoords parameter to identify the node/point because in analysis membrane structure keeps changing its position.
Is there any way I can select one node/point at a time so that I can specifically apply load at required position?