Actually, I decided to leave more than that and add to it. I just know someone, somehow, sometime, is going to make me revisit this in the future.

Code:

; Get users AD OU data by calling the getuserou function
$ou = GetUserOU()
; Take the string and split out the needed part
$SS = Split(Split($ou,',DC=')[0],',OU=')[1]
; Take the resulting string and parse left from the first space
$SS1 = Left($SS,Instr($SS,' ')-1)
;Take the string and parse right from the first space
$SSLeft = Right($SS,Len($SS)-Instr($SS,' '))
; Set the system variables
SET "SITE="+$SSLeft
SET "REGION="+$SS1

;Function GetUserOU()
;
;Author Remko Weijnen
;
;Action Returns the DN of the OU/Container which the user is placed in
;
;http://www.kixhelp.com/udfs/udf/112015.htm
;
;Returns If the DN eq CN=SomeUser,OU=SomeOU,DC=ad,DC=local
; it returns OU=SomeOU,dc=ad,dc=local
;
;
Function GetUserOU()
Redim $TempArray[0]
Redim $GetUserOU
$adSys = CreateObject("ADSystemInfo")
$TempArray = Split($adSys.UserName,",")
; Check if there's a comma in the CN, eg if the user name = "Surname, Name" AD returns "Surname\, Name"
If Right($TempArray[0],1) = "\"
$Start = 2
Else
$Start = 1
EndIf

For $Counter = $Start To UBound($TempArray)
If Len($GetUserOU) = 0
$GetUserOu = $TempArray[$Counter]
Else
$GetUserOu = $GetUserOu + "," + $TempArray[$Counter]

EndIf
Next

$adSys = 0
EndFunction GetUserOU()