As best I can see from FAR 61.73, as long as you have been actively flying w/in the past 12 months, you can take the Military Competence version of the commercial test and get an appropriate license.
Downside is that I think it would wind up being a single engine commercial for you, but, once you have that, should be relatively easy to get the multi-engine ATP topoff....or, in reading from 61.153, seems as if you can go straight to the ATP with an ATP written and Practical. Any of the ATP schools should be able to steer you to the correct path if I am in error.
http://ecfr.gpoaccess.gov/cgi/t/text....0.1.1.2.2.1.9
http://ecfr.gpoaccess.gov/cgi/t/text....0.1.1.2.7.1.1