You could "zip" the file(s) and email that file to someone who has Reunion 4 for the Mac. They could then make a Gedcom file that you could import into another program.
Unfortunately I don't have that old a copy of Reunion, so I can't do it.But you could do one of two things. 1. Go to their web site at www. leisterpro.com and find the email address for help. The company might do it for you, they are very friendly.2. Or, on the site, you could subscribe to their daily emailed newsletter. You could send a query to that newsletter/mailing list, asking for help. I'll bet someone would help you (it goes to users of the program as well as people at the company).