Hi Gamedev, MoI does not currently do any kind of special processing of the eraser itself, it just uses whatever mouse-click input the tablet driver sends to it.

With a regular Wacom drawing tablet, it is possible to customize what the erase does, under Control Panel / Wacom Tablet Properties. One of the options is to send a keystroke to the application. Then with a keyboard shortcut set up in MoI to handle that (under Options / Shortcut keys), that would allow assigning a custom function to the eraser.

Maybe the TabletPC has a similar setting in it somewhere?

It looks like if you have a TabletPC that is based off of a Wacom pen (which many are), you can install this: http://www.wacom.com/tabletpc/readme.cfm to get the same customization settings that are in a regular Wacom tablet, this should include customizing the eraser function.

Hope this helps!

- Michael