How I can display anycontent.php inside categories:
http://coppermine-gallery.net/demo/cpg14x/index.php?cat=5
Or album:
http://coppermine-gallery.net/demo/cpg14x/thumbnails.php?album=28
The effect I'm trying to realize is the same I can have on homepage using anycontent. New tables with my content in it.
I know is it possible to modify theme.php and mod function.php behaviour but I can't use it because also the homepage will be affect by the mod.
anycontent.php hasn't been designed for that. Either use the custom_header / custom_footer feature or go the way you're already aware of (modifying themes/yourtheme/theme.php). You can add a switch there to check which category you're in and only come up with your custom output if $cat != 0