Has anyone managed to convert Corel-converted .pdf back to a reliable .CDR?

Help needed: My PC failed:recently  2 years super work is in 'COREL-converted' .pdf but NOT .cdr (because I had health problems and missed a backup doh!)

Most of my pre-print-run work is in .pdf, but I do need to edit some details!

ANY help or advice is welcome.

I have been so despondent that I didn't think to try this yet. I have now bought a new hard drive and formatted it and re-loaded my original XV CD, etc. I do wish COREL worked on MAC, OSX

Nearly ready to go and try!

Thanks

RolandBryce