go to settings -> rooms and a/v devices -> add/edit a/v devices -> select the correct device -> edit -> IR codeset

from there look on the list of all the commands and use the learning function for the button you want programmed. If it is not listed on the rc9800i you will have to make it a user defined button, which sucks because you cant change the name and will have to memeroize what User Defined Button 1 does heh

hope this helps.