Regression testing is an important step to make sure that after committing a change to our software we do not make unwanted changes to other, untouched features. For larger and faster evolving software, however, executing all the test cases of a regression test can easily become a tremendous process which takes too much time to thoroughly test each changes separately. In our paper, we present a method to support regression testing with impact analysis based test selection. As a result, we can show a limited set of test cases that must be re-executed after a change, to test the changed part of the code and its related code elements. Our technique is implemented for a special 4th generation language, the Magic xpa development environment. The technique was implemented in cooperation with our industrial partner, SZEGED Software Inc, who has been developing Magic applications for more than a decade.