I'd suggest subscribing to the Cisco-NSP mailing list:
http://puck.nether.net/mailman/listinfo/cisco-nsp - you'll find all the answers you need. I'd recommend searching the archives first.
OT response: Bear in mind that because the 2950 is a L2 switch you'll find it quite difficult to get the IP addresses of connected devices unless they have recently pinged (or been pinged or otherwise connected in some way) by/to the switch - in which case they'll be in the ARP table. Unlikely, but possible. You may want to consider another solution or explain (on the NSP list) what it is you're trying to achieve.
We now return you to your regularly schedule program. ;-)
B.