I have a RCA universal remote RCU404B R55NA 2739P

something happened and now it needs to be reprogrammed. anyway i cant find the code list that came with it but i have searched and searched and have tried 10000000 of codes i found on-line and nothing works. any idea what else i can do. i also put new batteries in so it does work the light comes on and everything. please please help
Thank You, Teresa

Televison & Video - RCA - Universal Remote Control