>How can I issue a keyboard command such as "ALT+RIGHTSHIFT" on GOTFOCUS method of a textbox ?

You won't be able to do this with the KEYBOARD command as these are just "shift status states" and not actual keypresses that are passed. You can probably use the Windows API to check for these states in your GotFocus code, but I don't know which routine off the top of my head. Maybe someone else can jump in here.