I am working on an Animation right now.. and I am trying to just highlight the Translate X,Y,Z attributes along with the extend atrribute at the bottom of the channel box..

And it seems that I can only highlight either the three translate x,y,z or highlight the extend attribute on it's own.. because any other way i've tried i would end up highlightiing everything in the box..

i've tried using the "shift" key but that does not work.. is there a specific key i need to hold down.. so that I can highlight all 4 of these attributes.. and not everything in the channel box??