net connectivity at the top level using TCL

Hello,

I would like to use ncsim's (or simvision's) shell to find out the connectivity of a net.

For example, if I have a wire named clk in my top-level, I would like to get a list of ports that this wire is connected to.

Is this possible? Can you point me how to do that?

Thanks, 

Image may be NSFW.
Clik here to view.