I am have multiple lights that I would like to combine into one single AOV when I 'Export variable for each light'. Right now they all come in separate AOVs, I would like to selectively combine them into one.

Instead of Export Variable For Each Light

Change it to Merge All Lights Into Single Channel and then specify lights in Light Mask and/or light categories in Light Selection

Then that AOV will contain all lights matching those patterns

Repeat if you need more AOVs with different groups of lights