Ok, I couldn't figure out a way to set the path on the fly. Here's what I came up with. If anyone knows of a better way I'd appreciate it.

Thx,; Environment modification
$v = INSTR("%PATH%","U:\" ) ; Checks if script
If $V > 0 ; modification exists
Goto PathSet
EndIf
If @INWIN = 1 ; For Windows NT
$LF = chr(13) + chr(10)
$Message = "Hello, @FullName." + $LF + $LF
+ "Your systems local environment has been changed." + $LF + $LF
+ "Changes such as these should only occur ocasionally but" +$LF
+ "do require you to logon once again." + $LF + $LF
+ "We are sorry for the inconvience and if you have any questions" + $LF
+ "please feel free to contact your Network Administrator." + $LF + $LF + $LF
+ " Have a nice day." + $LF + $LF
$Env = ReadValue("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment","Path")
$NewEnv = "$Env" + ";U:\"
WriteValue("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment","Path","$NewEnv","REG_SZ")
MessageBox($Message,"System Update - @Date",4160,15)
$RC = LogOff(1)

EndIf
If @INWIN = 2 ; For Windows 9x
Shell "WINSET PATH=%PATH%;U:\"
EndIf
:PathSet