This is clearly not an easy task. The green-metal color was created in a way similar to how NMM's are created, but is very hard to replicate without going through the NMM technique.
This color will use alot of blending. Since you said you didnt want to do the NMM technique, maybe you will want to do layers instead, because it is easier. There are number of different possibilities.
1. Layering
2. NMM (witch you say you dont want to do)
3. Gloss varnish (which Rookie suggested).
4. Green metal paint (Testor's spray enamel paint sells a metallic green paint that I have used before, but I do not like it)
5.Gloss Green spray paint over a non-primed mini. This will give the same effect as outcast's suggestion, its just alot faster. Just make sure you put varnish over this because it can easily come off.
Hope this opened up a variety of possibilities for you, good luck