you can do it with Kixtart logon scripts, along with a thousand other things that you can't easily do with dos batch language.
otherwise, you could run a launcher script that would start your login script minimized with something like "start /m login.bat".
or you could write a little
VB wrapper program to hide your commands.
if it's a small environment, I would normally just use a standard script, redirect every command's output to nul, and put in a MOTD, as long as it's short and sweet the users don't get board. what's up, are your users breaking out before the script finishes?