passing argument to Main()

To all,

I had some note on the subject because I asked in the past but can't find them at the moment. I have a Nx.open (in vb) programme with the Main function defined as follows

Sub Main (ByVal arrsInMethod() As String)
 
if arrsInMethod(0) = "PA" Then
    gmiActionIdx = 1
    'other stuff
 
Else
   gmiActionIdx = 2
   'other stuff
end if	

the global variable gmiActionIdx is used by other programs to do/not not something
for example: if gmiActionIdx = 1 the GUI hide some buttons (on being displayed) and excite function #1 (if =2 show these buttons and execute function #2 when the user presses 'ok')

Question: How do I pass/set the argument to the Main(). I have 2 button in my NX custom toolbar button 1 (for option #1), button 2 (for option #2)

Thanks