PhotoWorks decals do not tranfer to eDrawings, but textures do. To add your image file as a custom texture:
1) Save the file in a custom folder (can be either local or on the network)
2) In the "File Locations" tab in the SWX options, add your folder to the list of Textures folders
3) Use a split line to separate the area to be decalled from the rest of the face
4) Right-click on the face and add the texture under "Appearance - Texture"
Note that masks are not available using this method, so you will have to match the background color of the image file to the color of the model to get a seamless blend.