The party split up!

So one of the fighters in the party wandered off with three npcs to "fetch some supplies". At session break he was preparing to attack them. The rest of the party are still with the main group of cult....er npc's. Is there a way to split the combat tracker so I don't have to repopulate the whole thing to run just the fighters combat?

Set the campaign option "Turn: skip hidden actor" to "On", give all of the PCs/NPCs that you want to keep in the CT, but not act in the side combat, a very low initiative (e.g. -20) to move them to the bottom of the CT, and then click the little "eye" icon (is that an eyecon?) to hide the entries at -20. Then as you move through the entries only the ones visible will be activated.

The main gotcha with this is that any effects with a duration on the hidden actors will be reduced at the end of each round. So keep this in mind if appropriate.