Create a new project with the same resolution and using the same theme. Open the source project as well. Captivate has a Multi Display Interface, both projects are in a tab. Select the slides to be copied in the Filmstrip and copy them to the clipboard with CTRL-C or with the right-click menu, Copy. Switch to the new project, select a slide and paste the copied slides (will be after the selected slide) with CTRL-V or the right click menu, Paste.
PS: I edited the topic title... to make it more meaningful to other users.
Thanks for the fast feedback, but there are no past funktion in the new Projekt and CTR-V is not possible. I work with power book. What schuld I do?
Try the Edit menu. On Mac you have to replace CTRL by CMND.