whilst I would use one of the vbscript Shell methods, I would use the Run Command method as this will allow you to start the Application silently. Exec will flash up a black CMD window which can be annoying.
[pre]
strCommand = chr(34) & "c:\program files\internet explorer\iexplore.exe" & chr(34) & " http:\\www.google.co.uk"
Set objShell=CreateObject("wscript.shell")
objShell.Run stCcommand, 10, False
[/pre]
In the first parameter, the chr(34) inserts a double quote into the string as the filename to run contains spaces.
The second parameter of the run method can take any value from 0 up to 10. http://msdn2.microsoft.com/en-us/library/d5fk67ky.aspx
for the list. 0 is silent.
The third parameter, bWaitonReturn, is either true or false to determine whether to wait for the Run program to exit before continuing. Usually, you'd use False if you want to fire up a program and exit the script.
Neil
Save the three lines above as iestart.vbs and stick in the logon scripts section of a user GPO to fire up IE and set the page to Google UK.