Thanks very much guys. Figured most of it now. Will come back to you with a couple of other questions. :-)

Funny thing is. My TV has a PC input but when i tried it before using the harmony it did not work. option was greyed out in menu as well. i was really upset about that. some of the reviews of my tv say it has a pc input and a couple did not mention it. i then tried the command 'input rgb' on the harmony and hey presto it switched to the pc input. the source button on the original remote would cycle through inputs but the pc one did not appear at all. Have i come across a supposedly disabled feature?