I don't think you cannot do this with KEYBOARD command because it only accepts key labels listed in ON KEY LABEL Command help topic. I don't know if it would work, but you can try to do this with WSH.

oShell = Createobject("wscript.shell")
oShell.SendKeys()
oShell.SendKeys("^+{+}")

For the list of keys see http://msdn.microsoft.com/library/default.asp?url=/library/en-us/script56/html/wsmthsendkeys.asp.

>I am trying to use the keyboard command for a (control, shift, plus sign)
>
>ctrl+shift++
>I have tired
>KEYBOARD ('{CTRL+SHIFT}'+CHR(043))
>KEYBOARD '{CTRL+SHIFT++}'