If you go in through the front door - meaning supported configurations - there's not a way. Windows only provides one active audio interface at a time. There are ways to side-step this using 3rd party solutions that will add latency. ASIO4all and Voicemeeter are two examples.

If you don't want to fool with this approach - then you'll need to decide which audio interface to use at a given time and either reconfigure for different tasks or adapt to one or the other and its limitations. If you adapt to always use the ID44 - then you lose the USB audio I/O of MODX. Therefore, you would route the analog audio out (Main L/R) from MODX to the ID44. Or, adapt to use the MODX to keep the USB audio I/O of MODX but now cable in your guitar OR other DI equipment to MODX's A/D input(s).

Thanks Jason,
whilst the MODX gives a great casual audio interface it is not high enough quality for use as a primary IO device. That being said and with your advice here I can see no problem with patching the MODX into the monitors during tracking of modx and repatching to the audient IO when done.
Thanks for your help
Kaz

Sounds good. Reconfiguration seems to be the prevalent suggestion from Yamaha here in this situation. Although you can cobble together something for convenience that prevents reconfiguration - the net result is degraded performance. For quality results, the reconfigure path is best and certainly is worth the juice if you don't mind the squeeze.