Sending CAD is no small feat, but to launch a Control Panel Applet is a cinch. There are several ways to do this.

The cheap and dirty way is:
Shell 'control nusrmgr.cpl'

The more elegant way is with RunDLL32.exe as follows:
Shell 'Rundll32.exe shell32.dll,Control_RunDLL nusrmgr.cpl'

With RunDll32, there are additional paramenters that can be passed. STFW for syntax and examples.

Here's one example:
http://www.thescarms.com/VBasic/rundll.asp
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