/diy/ - Do It Yourself

Have any of you tried to use custom, multiple digit 7 segment dynamic displays with microcontrolers?
I want to replace control board of dead coffee machine which uses one of them. It has 4 seven segment digits, 'clock', 'timer' and colon. 4/12 legs are marked with black dots, so I assume it has 4 backplanes. Apparently all I need to do is figure out what symbol is on what backplane and find some way to get three different voltage levels from atmega .
http://www.dataweek.co.za/article.aspx?pklArticleId=2382&pklCategoryId=31
What's the best way to do it?