(edit: hang on... got to debug this a bit. Trying to open that tab in control panel applet with AutoIt3 script.)
Okay, I couldn't figure out how to jump to tabs using the keyboard so I extrapolated until I got relative mouse coords. You might have to change the numbers for MouseClick depending on your screen res(I use 1280x1024.) But see if this AutoIt3 works:
Run("RunDll32.exe shell32.dll,Control_RunDLL sysdm.cpl,,3")
Also if the dialog opens but not to the correct window or tab try adjusting the numbers in the Sleep() call. The number is milliseconds. I'm using 1/4 second delay. Seems to work for most windows on my machines.