I might be late but why don't u get a diferent piece of ur sculpting material press that against the figure with chainmail, let that piece hardened and use that piece as a stamp
Yes it would be a reverse of the original piece of mail but I Can't see that it would matter really, either way you'll end up with a higher bit and a lower bit. I'd go with what Finn suggested though, in fact I kinda want to give it a go myself.
I'd prolly either put loads of little holes in sculpting material or and this one is easier. cover the area you want with sculpt then take a piece of chainmail from another figure, wet it thoroughly then press it into the sculpt then remove, repeat till whole area is done
I've heard a blunted hypodermic needle works wonders for this techique.