HideWindow

;-

You should just need this:

.lib "user32.dll"

FindWindow%(ClassName$,Caption$):"FindWindowA"
ShowWindow%( hWnd, nCmdShow ) : "ShowWindow"

You can copy and paste the Const values (SW_HIDE etc) from Robs code.

[Edit]
Use it like this:

hWnd = FindWindow( "Blitz Runtime Class", "my caption" )
ShowWindow( hWnd, SW_HIDE )

;-

Alternatively you can edit the .decls file entry for FindWindow, replace the class$ parameter with an integer (class%) then just set that parameter to 0 in your code and you don't have to worry about finding out the class name.