I'm using a Realtek audio card and driver. Unfortunately, the one device it recognizes in the windows sound menu is listed as speakers, and used both the front and back sets of audio jacks. Since I have both headphones and speakers, both plugged in, it chooses one to output to, prioritizing the front panel with my headphones. I need to create separate devices so I can have a headphones device and a speakers device, and as such, I need to change which jack they use, but I can't figure out how to change that. It would also help if I could select just one of the two jacks for each side instead of using both, so I can have left being output and right being input, on both the front and back.
This is a generic answer b/c the system details are unknown.
In some Realtek implementations the control panel (sound manager) has an option to mute rear speakers when headphones are inserted. By toggling this option, the system can continue to send audio to the rear jack when a headphone is inserted at the front jack.
In some systems, however, the front and rear jacks are connected in series and the amplified analog audio cable that goes to the headphones is disconnected from the rear jack when a headphone is inserted. See this stack exchange question for a detailed explanation. In this case you cannot configure the output from the software.