I actually managed to find a solution to this, but it took some tinkering...
Note: When speaking about BG:EE folder or BG2:EE folders it is, at least for windows in your Users/Documents/ folder.
1. First, you must export you character from the record screen in BG:EE. For some reason I couldn't do that in the final save file, so I used the one right before the battle with Sarevok.
2. Find that character file in you BG:EE "characters" folder (it's the one with CHR extension).
3. Open it with any text editor.
4. There is a load of crap there (it is not meant to be viewed in a text editor) and find where it says MANLEY#SMANLEY#M, where # can be any number.
5. What you now need is two bitmap (24-bit) files with those filenames (you should substitute the number for what you saw in your character file), the one with and M with in the end is the big one in your charcter screen, and it should have the size 169x266 amd the one with the S in the end should be of size 58x84.
6. You can put any portraits in those that you like, I myself took the opportunity to change mine, otherwise you have to look for another portrait pack to find the specific one you need or use something like the Near Infinity tool to extract them.
7. Place those files in the portraits folder in the BG2:EE folder. I had to create this directory.
8. Run the game, you don't even have to start a new game.
Please feel free to ask questions if you have any, I will answer as quickly as possible, however, Sweden plays in the world cup playoffs tonight, so between 2045 and 2230 CET I will be very busy...
Hope it helps.