Got a good image editing program like Photoshop or Paint Shop Pro? (Not MS Paint, because it won't save as anything but .bmp which is too large)
Hit Print Screen once you've made yourself, and then paste that image into the program. Crop it down to size so it only shows the SP character on the screen, and then save it as a .jpg or .png (.png is better quality and smaller if you have the option to save it as that). Then attach it via the attachment option at the bottom of the post page.