If the 'Private Tanks' is controlled by slash commands, you could have an IS Boxer mapped key, with as many steps as necessary. Have it send to each window, as desired.

You'd just have to edit the wow macro, in IS Boxer.
Or possibly set it up using {FTL} or {SLOT} commands, so it is dynamic based on your team.

Not really sure what your process is to set the tanks, having never played with Vuhdo.