What cheat device do you have? (or take a picture of it)
Are you able to backup your save to your computer? I can apply the cheat for you if you want.
Finding/porting that code will take some work.
01C089DA means it writes C0 to DA89. If you want to have a go yourself, open the jp game and en game together in something like visualboy advance, and look for similar areas or memory in near DA89, so you can try and work out the offset.
I can't find it today sorry
Here's a image of my cheat device. It work fine with all other codes. I just think this code is faulty as it didn't work with you but then worked with you afterwards. I don't know how to port save files from cartridges to my PC and I have no clue how cheat codes are made