HamQTH is a very useful site, and I really like CQRLOG.  I've got it making good looking QSL labels using gLabels designer.
CQRLOG has the ability to look up callsigns on HamQTH (or QRZ.com) abd it reports the addresses in the New QSL screen, and then promptly forgets them.
I wish that the addresses would be remembered and put into fields in the Export QSLs For Label Printing dialog box, or perhaps better, I wish someone could write a simple program to extract the callsigns from the *.qsl file generated by CQRLOG, go online to HamQTH and return the addresses so that they could be  printed using the gLabels designer.  
I don't have the programming skills or I'd do it.
73's
Steve, K0GUZ