You will want to cross reference section 25.0 Moving Maneuvers.
Moving Maneuvers include climbing, swimming, riding, stalking, and any complex or unusual movement.
The general gist of the rules here is that the GM picks a difficulty for the entire maneuver. Table T-4.1 gives some examples and Appendix A-1 expands on this in relation to specific skills. You will want to look in these appendix since that contains a bunch of movement rates - why they put them there I do not know. Check A-1.6 for some good info on standard movement rates.
The way I typically run it, the more the player wants to do in a maneuver the more difficult it becomes. That increase in difficulty should be commensurate with the difficulty of the added action. So if the added action by itself would have an Easy difficulty, increase the overall difficulty of the total maneuver by two steps. This also applies if the wish to cover more distance than one might cover when moving safely / cautiously.
Remember too that if the player rolls poorly, they may not complete all their actions. The result on that table is a percentage of the action completed, so have in mind how much each portion of a maneuver takes up from the total maneuver. Conversely, if they roll well they may have some action left over.
Finally, this is a super flexible system, so the players can ask for the moon. It is OK to say to the player that any combo of actions or single maneuver is too much for one combat round.