Copy the sprite to a second layer.
Do the glow.
Create an empty layer below the sprite.
Select sprite layer.
Go to the selection menu and select layer transparency. The sprite should be outlined.
Merge sprite layer down with empty layer.
Effects will now be baked into layer.
Select clear from menu mext to file menu to clear the sprite from the middle of the glow.
Voila!
Do the glow.
Create an empty layer below the sprite.
Select sprite layer.
Go to the selection menu and select layer transparency. The sprite should be outlined.
Merge sprite layer down with empty layer.
Effects will now be baked into layer.
Select clear from menu mext to file menu to clear the sprite from the middle of the glow.
Voila!