I'm not sure if your question has been answered or you have already solve the problem but here is what I would do, and it does include a batch file but you do not have to distribute it to all the clients
Step one create a share or use an existingshare where you can store the the batch file.
Like \\%server%\support$\%batch.bat%
(you should probably make it a hidden share so when people use things like network neighborhood they cannot see it)
the command choice /t:3,n this will make the system pause for 3 seconds and then continue the pause is mostly to allow server processing to complete
the next command should be the net use command to map to the Z:
and last a command that will delete the link from the start up menu so users cannot play with it if the happen to go into the startup menu
to implement it you need to do the following
on the logon script create a command that will copy a link to the batch file to the windows start-up menu since all startup items go afterthe logon script the batch command will work, the advantage of coping the a batch file link insted of the batch file is that you have a batch file you can use in a central location and you can use it like a second part logon script.
I hope this helps with the solution to your problem.
Agustin M. Rodriguez, MCSE