Originally Posted by NickP 1K

I just tested this using Remote Desktop 2.0 and it does work to send the F keys from your keyboard (on a proper imac keyboard just press the F key, On a Macbook try it as is and then try FN + F key) Pressed F12 in Excel and "Save As" opened up as it should on a real Windows PC. That same key mapping should work for a pre-boot RDP session.