Fred,
If you can obtain the RAS connection handle (did you initiate the connection?), you can use RASGetProjectionInfo in RASAPI32.dll to return the IP address of your current connection. This function returns a structure that makes it a little difficult to accomplish this in native VFP (you are obliged to use a C/C++ API).
I don't know how to get the handle that another process started (never had to worry about that one).
Good Luck