Coax output? What are you asking? For video from HDMI and audio on coax? If that is what you are asking No is the answer as the VIP's only output HDMI or component for HD video and optical or left/right analogue audio. Other possibility are asking if you can use HDMI and the RF (coax) NTSC channel out then that will work.
It would be better to explain what you're trying to accomplish. Not just the "split hdmi" but what is the end point? you want to hook up two TV's? and one of them is old, having no other connectors ?? etc..
Also understanding the nature of HDMI .. as time is moving on, companies are calling on enforcement of HDCP, and in the licensing spec for HDMI/HDCP (HDMI licensing *not* HDMI specs) any analog output is to be denied on HDCP protected content enforcement. The push is currently coming from HBO .. its only a matter of time before others start doing it too.
So ... what were you trying to accomplish (and confirm please, 722 or 722k receiver?)
You can use a splitter on the home distribution/TV2 out to get TV1 out through coax while it is hooked up through HDMI. In the Modulator Setup you have to turn TV1 out to the same mode as your TV2 out (air or cable) which will get you a picture of TV1 on channel 62 or 75 (by default), or whatever you select.