Best is to use jb 4 where the mcf properties are directly exposed as jmx attributes. However, I don't think even I would recommend using jb4 for production at this point.
you probably can't set properties through the jmx console in earlier versions since you have to supply an xml Element and there is no property editor for that. You could write a jsp to specifically call the DS mbean or write a property editor. Then you probably have to call stop and start on the DS mbean to get the properties copied.
Right now mbean persistence is at a rather experimental stage and only implemented at all in jb4.