Odor/Smoke filter for Microwave over Range, recirculating

[JimK]

I have a 3 year old Whirlpool/Amana Microwave over my range. I live in a condo, so cannot vent this outside, and because it is newer the grille on the front vents straight up into the bottom of my cab right at the doors, rather than straight out like my old one. Whirlpool does not have a replacement grill that vents straight out (horizontal). My ceilings are 10', so I can change the MW to vent out the back and then duct it up in back of the cab, up to the space above it - I have 2 1/2' open to the ceiling. If I do this I want to add some sort of filter that absorbs odor and smoke. Do you have a recommended filter? - I can mount it above the cabinet hidden from view by my crown molding. Is a normal MW fan powerful to overcome the pressure loss associated with an additional filter (besides the grease filter on the bottom of the MW)? Is there a company that makes a retrofit like this? Thanks.