I found the codes in this page http://remotefinder.rca.com/
Codes for Jer 321, Jer 323 and Jer 422.
To introduce it to your universal control Jer 323:
1. Press the device button you need (for example, TV)
2. Press the input key and keep pressing it while introducing your code (for example, Sony Tv: "Input+1218")
3. That will work fine. =D