R groups: special characters, in MarvinSketch

Hi, I would like to be able to create R groups with non-number characters (namely Greek letters [like alpha and beta] and Latin letters like N) in them, along with subscripts and superscripts. For example, see this SVG from Wikimedia Commons that I would like to mimic in MarvinSketch (Dw, I realize it was created with a software other than MarvinSketch [probably, at least, I'm asking the author how he created it]).