AFAIK, you should position your icons according to your preference, and then select them all, and then snapshot icons. If we are talking about icons in a window, select contents, snapshot icons, then snapshot window.
It wasn't always as percise as I wanted it to be, but it has helped somewhat by using the above-mentioned method. I think that you can't really manipulate where the RAM drive icon should be.
All in all, a very good question. Anyone else with some hints?
This reminds me of something which I wanted to know. How do I make the names of ICONs to be without the gray (default) background? When ever I would put a nice backdrop in OS3.9 I would always get the ugly gray background behind the letters of the names of all the icons on the desktop. I'd just like them to be backgroundless so to speak. :-)