please help copying curves to drive a node

Is there a way to copy a curve from one type of datablock to another one that is completely different?

What I want to do is to use f-curves to control the x and y displacements for a translate node in the compositor (2.53b). A simple ctrl-R click adds curves for the inputs to translation node but they are tough to freehand edit. What I want to do is animate a picture frame object so I can see how the translations look and adjust them smoothly. Then I want to take the x and y curves from the animation of my picture frame I have just produced and stick them in as the curves to control x and y translation in the node so all I need to do is scale them up to use them.

but when I copy the x curve from my frame object to the clipboard, then select the curve for the x input to the translate node and hit paste, nothing happens. Is there a way to do this or must I try to copy the curve shape by hand??

Let me rephrase this. I want to use f-curves from the x and y positions of an object animation to control the x and y translations in a translation node in the compositor. The problem is that I can’t copy and past an object curve to the x or y translation node curve. In addition, when I make a driver, it doesn’t seem to change the values in the translation node.

Is this possible? Has anyone had any luck using drivers to control the inputs in compositor nodes?