That's sort of what the "Number to: Rename Component" option is for. When this is set, whatever numbering setting you use will change the name of the component instance instead of placing 3D text. Then in Layout, you can use the label tool with the Component Instance option. This will give you the text created by Number Components in SketchUp. This could still involve an awful lot of clicking, but the numbers will be there automatically.
For example, you could select all your windows, use "Text n" and set the prefix to "Window ", "Number to: Rename Components". Then in layout, just click on each window with the label tool and you'll get "Window 1", "Window 2", etc. for the text.
There's a Ruby API for Layout now, but I haven't looked at it. It's not interactive so the plugins don't run in Layout. It might be possible for a plugin to create a Layout file with the numbers labels all arranged automatically, but I don't know.