Reqired Subject's Tag?

How can I add a reqired field in the posting form that allow users to chose one of the givin tags to apply it as a prefix for the subjects title? (tag options are shown in "radio" way and non are selected by defult)

for example:

0 New Release
0 Qestion
0 Bug

a user must choose one of these tags and the chosen tag will appear as text before the subject's title in order to easly view a forum.

this topic may help: http://punbb.org/forums/viewtopic.php?id=9808