Thank you. Yes, that works.
After follow the steps you told me, fc-cache said this:
/usr/share/fonts/OTF: caching, 23 fonts, 0 dirs
/usr/share/fonts/TTF: caching, 75 fonts, 0 dirs
/usr/share/fonts/ipa: caching, 5 fonts, 0 dirs
/root/.fonts: skipping, no such directory
/var/cache/fontconfig: cleaning cache directory
/root/.fontconfig: not cleaning unwritable cache directory
It seems that the step I was missing was to edit local.conf, remember that the ipa directory was already added to section "File". About calling mkfontscale, the package already came with .scale, .dir and .alias files, so I jumped that step. Also, I was unable to locate a local.conf file so I created one in the font.conf directory in order to be able to follow your instructions. After doing that, that five fonts exists only in /usr/share/fonts/ipa and they can be used normally.
Thank you again, goodbye.