How to displaying images from CPG on my other html files?
Static html pages can only contain static content. Dynamic content (like content taken from Coppermine) can only be inserted into dynamic (i.e. PHP-driven) pages. However, you can add content taken from Coppermine on non-coppermine pages, using one of the mods posted in http://forum.coppermine-gallery.net/index.php?board=57.0
The mods there (as all mods) go only supported there, on the threads that deal with them.