Setting another program maximized

Hey guys,

I just cannot get this code to work. I am trying to make another programs window fullscreen so i have been trying to double click its window (which makes it fullscreen normally)

Here is what I am using. I wonder is there a simpler way to tell the program, run in fullscreen mode. If there was a better way than below I would love to see it.

Thx
KT
VB Code:
Private Sub Command314_Click()
Dim abc As Long
 
param = MakeLong(200, 200)
 
Call SendMessage(whwnd, WM_LBUTTONDBLCLK, 0, param)
 
End Sub
 
Public Function PadString(ByVal sIn As String, ByVal Length As Long, ByVal PadChar As String)
 
If Len(sIn) < Length Then
   PadString = String$(Length - Len(sIn), PadChar) & sIn
Else
    PadString = Left$(sIn, Length)
End If
 
End Function
 
Public Function MakeLong(ByVal LoWord As Integer, ByVal HiWord As Integer) As Long
 
MakeLong = Val("&H" & PadString(Hex(HiWord), 4, "0") & PadString(Hex(LoWord), 4, "0"))
 
End Function