A question about .pro files

I've tinkering away at NI and I've come across the "SmashingWave.pro" from Icewindale EE that I'd very much like to use for a custom BGEE spell. On creating a spell for some reason this .pro doesn't register as a potential projectile despite the .WC and .BAM files being prepped and ready for use. Are .pros a restricted file that are limited to use in their own games of origin?