You'll have to take this into Audition, where you can apply a DeClipper that works surprisingly well.
Basically just echoing what Jim said...
I've had a lot more success in Audition with this wort of thing than in PrPro. I think DeNoiser is the one I usally use, but there are others as well. You'll probably need to mess around with a couple different filters (and of course their paramters -- but not all at once) to get the best result.
That said, don't expect any miracles. I now it's been demo'd before but due to its inherently 'transparent' and omni-directional nature, audio repair is at least 10x harder than video repair and 100x that phot touch up. Sometimes I have been surprised by the result too, but it really depends on the source material and how perfect you need the fina clip to sound. Let us know how it goes.
I forget where to find it, but in Audition, there is a "Reduce Harshness" filter that can work wonders, has saved very loud wedding reeception recordings for me.