The terminology you use is so cryptic, what you are asking is unclear to me. Do you already have steering wheel controls, or do you want to add them?
If you already have them, and you are adding an aftermarket head unit, you need to select a head unit with infra-red remote controls. Then you get an adapter that reads the steering wheel switches and spits out the appropriate infra-red command.
You will therefore need to mount the infra-red transmitter LED in a location that will be read by the sensor in the head unit.
I'm sure you can Google "steering wheel control adapter" or something similar...
2001 Bonneville SE - Dark Bronzemist Metallic - Mods: 180* thermostat, iPod adapter, Digital OnStar Upgrade
Planned Audio System upgrades: Front & Rear 7 Band Equalizer, Amps, Hands Free Bluetooth Cell Phone kit
Planned mods: Front PEM, Ported LIM, Ported Heads, ZZP SR Rockers, Aluminum Gaskets & Reprogram PCM