Without the .mo files none of the translation will work. They are the binary ones getting loaded by WordPress.
The .po files only contains the raw translation strings, which are only used by translators. If you’d like to use these, they are either available on Transifex or in the plugin languages folder.
Overwriting any plugin language is easy. Just place your own .mo file in this folder: /wp-content/languages/plugins/cpac-da_DK.mo’. That’s it! Works for all plugins.
If you rather have your admin columns language file in a theme. Place your .mo file inside the “/languages” folder in your theme and place this code in the functions.php:
function cpac_load_cpac_translation_from_theme( $mofile, $domain ) {
if ( 'cpac' === $domain ) {
$mofile = get_template_directory() . '/languages/' . $domain . '-' . get_locale() . '.mo';
}
return $mofile;
}
add_filter('load_textdomain_mofile', 'cpac_load_cpac_translation_from_theme', 10, 2 );