rgr, doesn't really look like it's gonna work
please, confirm me, is it for WOE or SF2E?
decals for the second series (SF2, SF2V, SF2E, SF2I) need to be stored at a specific place to work
go to your main addons folder (exact place is depending on system, if you're under win xp, it should be under "my documents\Thirdwire....." (please soembody, confirm this, mine having been moved, I can't check default path)
then, Objects
then, Decals
then a folder with your plane name (exactly the same as the pain folder for this plane) e.g Su-27SK
then a folder with your skin name e.g indo
you can drop your decals into that very folder
now, the fileformat line should read: FilenameFormat=Su-27SK/indo/indoni for a decal named indoni
if you use WOE, decals could even be stored right away in the skin folder...the only trick being in fact to know what the game use as "root" for the fileformat ...("decals" folder in the SF2 series, "aircraft" folder in WOE)
Hoping I was clear enough
don't forget to adapt level as required