Trigger with the "clock" you want. Whether you use Chan "A" internal [level and proper polarity], or external [level and proper polarity] is up to you. Then view the RGB on Chan B [with chan A triggering] or Chan A with external triggering

After all, it's for your viewing pleasure.

 

But the sync H or sync V would have to be on a SEPERATE WIRE than more Chorma channels

For my composite i "can not" seperate my sync H and sync V to trigger my Oscope

 

You seem to want to resist reading material. Take a look at the very clear illustration on this link - http://electronics.howstuffworks.com/tv9.htm - and you will see what to look for. You can easily trigger on those synch signals. It also give timing info, so you will be able to set the horizontal sweep.