Most combo DVD/VCR units I've seen have seperate output sections for the DVD section and VCR section. You can run either component or HDMI for the DVD section and probably composite for the VCR section. You also need to run audio cables to the TV and/or AV receiver from each section. You can try HDMI for the DVD section, check the specs on the unit to see if it can output the VCR section over HDMI also.
What model player is it by the way?
What model player is it by the way?