Allow call handling custom rules to forward calls to main phone number

I need to have a phone number, that when direct dialed, forwards to the TOP level of the auto-receptionist for our main company phone, so that if we are open, the IVR menu plays and if we are closed, the call is sent to voicemail. Right now, I am having to create a custom rule that forwards to an external number, purchase an external "dummy" phone, forward the calls to this external number, and then have that phone re-forward back to the main phone. I worked with support and there is no other workaround for my needs.