I have a computer built from hand-me-down parts that has onboard sound. I have a set of speakers and a pair of headphones I would like to use, and currently I have to dig around behind the computer to switch between them. The motherboard has pinouts for front-mounted headphone and mic connectors that, when connected, will automatically turn off the speakers and route all sound input and output through the front-mounted ports. Unfortunately, the case doesn't have connectors.
Can I make my own front-mounted connectors? How much would it cost, and from where can I buy the necessary parts?