I have been trying grep and regular expresions, but my regex is not up to solving this particular problem.

What in particular did you try, and what didn't work? Effort demonstrated through posted code is generally taken as a sign of good faith.

It's fairly simple to test for the existence of a particular string, say cups-1.5.2-9.fc16.x86_64, but what is your intended behavior when the version number changes? My solution might look something like

perl -e '@arr=`rpm -qa`; if (grep /^cups-\d/, @arr) {print grep /^cups
+-\d/, @arr} elsif (grep /^cups-/, @arr) {print "Empty set\n"}'
[download]

Expanding it to handle other leading strings would be easy, though in the general case you may want to escape the string, e.g. /^\Q$name\E-\d/