loc 22550 is right. Let's simplify it all:
Open Clb: Give me climb thrust and maintain the speed (selected or managed) with the elevators.
Clb: As above but please obey any constraints.
Exp Clb: As for 'Open Clb' but fly Grn Dot speed. (ie max gradient).
CI 0 gives max rate of climb
Cheers
mcdhu