Vista - Assistance with script for changing printing method

I'm trying to write a script that will:
run on each workstation on a network (startup via GPO, or push via
SMS)
Go through each profile in the registry (HKey_Users) and find each
network printer that is mapped for a give user (\\printers
\printername)
find that printer name in a table (printername, IP address)
Delete the printer mapping from the user profile
Add the printer back as an IP printer to the workstation
If this printer was the user's default, make the new IP printer the
users default.

Basically, get rid of the print server for existing user accounts.
Anyone have something like this or some script to work with? I don't
know how to recurse through HKey_users and find the existing printers.

Thanks