The end result is below. I got seriously pressed for time and decided to forego elegance in favour of a more brute-force approach. The functionality in a nutshell:
- Find current network printers (don't touch local) from any of my three old servers
- Find current default printer
- (Try to) connect to the printername on one of the two new servers ($newserver). If that fails try the other server($altserver).
- If the current printer was default earlier - set it as default now.

 Code:
$printers = EnumPrinterConnections2()
$defaultprinter = GetDefaultPrinter()
$newserver = "novmprthp01"
$altserver = "novmprtdiv01"

For Each $printer in $printers
;	Handle only network printers
	If Left ($printer, 2) = '\\'
		$oldserver = Substr($printer, 3, 9)
		$printer = Substr ($printer, 1, InStr($printer, ',') - 1 )
;		Handle only printers on the old printservers		
		If ($oldserver = "NOPRTHQ02" OR $oldserver = "NOPRTHC02" OR $oldserver = "NOPRTHC03")
			$rc = DelPrinterConnection($printer)
			$newprinter = Split($printer, $oldserver)
			$newprinter = Join($newprinter, $newserver)
;			A quirk in the use of the Split + Join funtions above may return a backslash too many
			If Substr($newprinter, 3, 1) = '\'
				$newprinter = Substr($newprinter, 2, LEN($newprinter)-1)
			EndIf
 			$rc = AddPrinterConnection($newprinter)
			If $rc > 0
				$newprinter = '\\' + $altserver + '\' + Substr($newprinter, InStrRev($newprinter, '\')+1, LEN($newprinter)-1)
				$rc = AddPrinterConnection($newprinter)
			EndIf
			If $printer = $defaultprinter 				                        $rc = SetDefaultPrinter($newprinter)
			EndIf
		EndIf
	EndIf
Next

Exit


Thanks for your help - I hope this may be of help to someone else at some point.
_________________________
Share and enjoy - Kjetil