How to make penetrations in preexisting corrugated siding? – GreenBuildingAdvisor

Hi all, 

Are there any drawings, photos, or guides for how to make penetrations in preexisting corrugated siding that is attached directly to the plywood sheating? I need to make some penetrations for a bath fan, ac line sets, electrical outlets etc, but it’s not feasible to remove the panels since they are large and caulked to each other. The siding is also fiber cement, not metal but I assume the process should be the same.

My thought was to trace out a sufficiently thick mounting block, cut the siding as close as possible to the dimensions of the block, attach the blocking to the sheathing using sealant and screws, drill for my penetrations in the mounting block, then caulk all 4 sides of the mounting block to the corrugated siding. 

Does this make sense or is there a better way?