Is there any way to open files saved in Corel 7 with X4 without resaving all docs?

We had a hard drive crash on one of our computers and decided to update programs while we were reinstalling everything.  Unfortunately, now no one else in the office can open any of the files saved on that machine.  I know we can go back, open each file on that machine, resave to the old version, but that's a lot of work.  Is there any way to accomplish this without having to resave?