Or [in Windows] you could go to All Programs >accessories and select snipping tool, click on area of map you want saved and save that image. I have found that it will save as a much smaller file than paint.Once you've done the export of the entire map, find the file on your computer.
Right click on it and go to "Open With" and choose "Paint" , it should be on your computer as part of the windows install
In Paint go to "Select" and select a square around the area of the board you want and then choose "Crop"
Then "Save As" to save it with whatever name/format you want.