I don't want to duplicate a composition, I just want to create a new one that has the same dimensions, frame rate, etc. as another composition so they "match." Kind of like in Photoshop, when you want to resize an image, you can select another image from the Window menu to use those dimensions. Is that possible?
Right now -- it seems to this newbie -- I have to write down all the properties so can change them in the New Composition Settings window.
Did you know that if you make a new comp, it has the same settings as the previous comp you made?
Besides, it's dead simple to make a comp with ANY kind of settings. I'm a slowpoke, and it takes about 20 seconds to make one from absolute scratch.
Furthermore, 85% of the most common comp settings will be found in the comp presets.
You can drag the original comp onto the "create new composition" icon. This will create a new comp with the same settings as the original, with the original composition nested inside the new comp. Remove the original comp from the new comp. Rename the new comp.
Alternatively, you can right click on the original comp, choose "composition settings", and then save those settings as a preset to apply to future comps. If you work with a particular size comp over and over, saving a preset can be very useful.
Hope that helps!