please see:
http://www.qcad.org/rsforum/viewtopic.php?f=31&t=1177

from LeoP

" What would be really useful is a method to select entities by type, rather than by location or layer.

It could have a user interface like the snap command with buttons for the entity type to select, or like the line command with a drop-down box.

This would enable one to quickly select e.g. all texts in a drawing for subsequent attribute modification. Now one has to select each text individually if the texts are scattered over the drawing and layers..."