Since you mention Cp files and not Cptx files, I'm assuming you must be on Captivate 3 or 4?
If you do not have any backups of the project files, I have very bad news. There is no way to import the published SWFs back into Captivate to recreate the original project files.
In Captivate 4 and 5 you can set it to create backup versions in case of corruption of the original project file. Cp5 also now allows you to recreate the entire project file from cached files. I'm guessing that neither of these options are available to you?
Yes, that's correct - I'm still working in Captivate 3. It's a little bit late for backup versions, don't you think? To recreate projects from cached files would be the far best alternative, but then I have to ask for money to update to Cp5 ... Is it possible to edit swf files in some of the other CS applications? I have CS4. Or to convert the swf files to something editable? It is mostly text editing I need to do.
There may be tools around that will decompile SWFs, but I'm afraid I cannot help you further on that one.