Sorry to hear that your VZ-10M is not feeling well. Unfortunately, from what I understand, the LCD in the VZ synths was a custom part. So, I'm afraid you won't be able to find any kind of standard modern (or even not-so-modern) equivalent part to easily replace it with.
Your best bet is either to obtain another working VZ-10M (or Hohner HS-2/E, re-branded from Casio) instead, or a non-working VZ-10M, VZ-1, or HS-2/E that has a good screen that you could swap to yours.
Occasionally, you see VZ-10M and VZ-1 units appear on ebay (though I've never seen a Hohner HS-2/E). There was a VZ-10M there recently, although the listing seems to have disappeared. Set up a search on ebay to email whenever new listings arrive. Craigslist is also a good place to check.
- Matt