Certainly!
Here's the example from CO:
Conventional infantry should refer to rules for ammunition costs and weights (see pp. 260-285, A Time of War) and are assumed to carry five reloads for their weapons as a standard combat load. If the infantry are armed with non-plasma energy weapons and are often stationed with fission- or fusion-powered vehicles (i.e., they spend a maintenance cycle with such a vehicle after a maintenance cycle involving combat), then the ammunition cost is divided by 10, because their power packs may be recharged for free and only worn or damaged packs need replacing.
So, for the bog-standard Auto Rifle, go to page 266 of AToW. It's "Cost/Reload" value is 80/2. This means a single "reload" is 2 C-Bills. Looking to the column on the left, you see the "Shots" value is 30, so that means a "reload" is 30 rounds. But CO only cares about "reloads" not "rounds". Five reloads would cost 10 C-Bills (5 x 2 = 10), which is the per trooper. To get the peacetime per month cost, you divide that by 4, for 2.5 C-Bills per month.
Now, for energy weapons, it's a little trickier. Looking under "Laser Rifle" on page 267, you see a single dagger where the reload cost should be. That note refers you to page 306 (the Power Pack table). Page 306 gives you a wide variety of Power Packs to choose from, and really, only you or your GM limit your choices. For your purposes, I'd choose the "Standard Power Pack" at 5 C-Bills a pop, so five of those would be 25 C-Bills. Dividing by 10 yields 2.5 C-Bills per trooper. Dividing by 4 yields 0.625 C-Bills per month.
Hopefully that helps!
EDIT: Thanks to Maelwys for the corrections!
