I did some looking around on the net and found MY particular drain.
UNFORTUNATLY it is supposed to be installed and tightened down BEFORE the shower pan is set!
Mine is the solvent weld brass drain pictured on this site:
It is installed much like a basket strainer on a kitchen sink and then solvent welded to the plastic trap riser.
You can E-mail the company that manufacturs these drains from that link and ask them if there is any hope, but it looks as if the bone-head plumber forgot to install the drain before setting in place!
doesnt look good my friend!