As far as I know, no it can't but, actually, you don't have to insert those files into a zip. If you create a folder with the same name with zip file, DCS can run it too.
So, if you put your files in a "FA-18C-CPT-TEXTURES" folder in the same place with FA-18C-CPT-TEXTURES.zip, it will be fine. DCS will read your files first!
Note: Be aware; this may break Integrity Check. You may not fly F-18 in multiplayer servers that check I.C.