installworld with specified ctime possible?

Hello, I'm asking here since I don't expect to get an answer _at_questions.

Does anybody know a trick how I can have the files, installed by installworld, 
have a specified ctime? Reason is, if I do a `find . -ctime -5` and I 
upgraded world yesterday I don't want to get the system files but only the 
files I modified during the last 5 days...

Thanks a lot,

-Harry

P.S.: I saw that install(1) doesn't have a option to set ctime..., so it's not 
that easy I think