Importing Monster PNG File..

I am trying to import a nes sprite into RM2K3. I am using Infraview to convert the file to a 256 color .PNG file.. But for some reason it doesn't work. It works as a 256 color .BMP file put it looks all messed up and transparent when put into the game. Is there a tutorial for importing graphics or monster graphics?

Thanks
Korrupt_Ikonz

P.S. I haven't figured this one out yet.lol.

Open it in paint recolour the bg make it like 5 pixels bigger and repaint that same colour as bg

yeah, try that, I think it should work.