i have a template of an animation with different spaceholder for footage. ( using after effects 5 )
now i want to copy part of the composition and paste it at the end of the timeline to get a longer clip.
but the footage i put in is now at the beginning and the end - refering to the same clip.
how can i duplicate the part of the composition including the sub-compositions?
You can import the project into itself.
You can save a second version of the project and render what you need out of both and put it together in your editing program.
You can duplicate the sub-comps too.
You can get the true comp duplicator script.
There are probably other ways.
Duplicate the original comp in the project window. Give it a new name. Open the newly-duplicated comp, and replace the desired layers with new stuff. Now you can nest both the original comp and the duplicated comp in a third comp, and you'll be fine.