It is not a perfect conversion but I tried it a year or two back with later Flare and RoboHelp projects and it did a pretty good job.
You will need to contact @johndaigle via the Private Message option on this forum.
The only other option I can think of would be to generate a CHM output from Flare and then see Reverse Engineering (grainge.org) on my site. I'm not sure how well that would work compare with John's script.
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As Peter mentions, I'm happy to provide a Flare to RoboHelp Project Converter. If you'll please private message me, I'll send you a link for the download. I am not certain about the compatibility of the versions you mention, but it's easy to set up and try it out.
John Daigle Adobe Certified RoboHelp and Captivate Instructor Newport, Oregon