You're passing the control itself to the Sub (see next sentence), so use the passed control variable rather than whatever you are trying to do accessing it via the parent variable's With statement. Also, why is it a Function if there is nothing being returned?

Code:
 With objPARENT
  If TypeOf objPARENT Is Form Then
   objCTL.Left = (.ScaleWidth / 2) - (objCTL.Width / 2)
   objCTL.Top = (.ScaleHeight / 2) - (objCTL.Height / 2)
  Else
   objCTL.Left = (.Width / 2) - (objCTL.Width / 2)
   objCTL.Top = (.Height / 2) - (objCTL.Height / 2)
  End If
 End With