How can I conceal an over-the-range microwave?
You used to be able to buy microwaves that you could apply cabinet facing to, but a quick google search doesn't show any examples.

There are a number of ways to put a cabinet door over a microwave, and it looks like the following would probably suit your needs best:

http://www.houzz.com/hidden-microwave

There is cabinet hardware that lifts the cabinet door out and up, so if properly mounted you can have the bottom venting portion of the microwave open for the stove, and cover the rest of the microwave with the same cabinet facing you have in the kitchen.  You just lift it up to access the microwave.