A good link with all types of measurement conversions: [link=http://www.sciencemadesimple.com/conversions.html]Conversions[/link]

So, the cg is 76.2mm behind the wing LE (measured at the fuse, not at the wing tips).

But still, I find it terribly odd that your plane, a trike, sits on it's tail. Something is really, really wrong there. Please post when you find the problem. I'd like to hear about it.