[Chimera-users] Get xpos and ypos of selected residues automatically

Dear all, Here is my problem: I need to write a cmd script to use 2dlables automatically assign some annotations to some selected residues for many different proteins. However, I did not know the xpos and ypos for these residues and for different proteins there will be different residues which need to be assigned. So, is there any method to get the xpos and ypos via some commands when I only know the residue identifiers? Thanks Wei Li 2010-6-3