What you do is to create a PSP image with 2 layers. Put all your graphics on the top layer. On the bottom layer, fill it in with white. Then, set the layer opacity to 1%. Save this as myfile.pspimage.

Then, use the Export Wizard to export a PNG and on the Transparency tab, select 'Image Transparency' and continue to save the file as myfile.png.

Load the file into the remote. Even though the image looks transparent, the entire rectangle can then be pressed.

If I recall correctly, there's a discussion of how to do this in the PPENG Help File. Press F1 while inside the software and search for transparency if you have not already done so.

Lyndel