nd help opening powerpoint in coreldraw

I need some help.  I have slides in powerpoint that I need to turn into booklets. The printing company I used to work with simply asked for my ppt files and they somehow opened them in corel and edited them.  I'm not working with that same printer anymore... I've hired a corel draw guy to help me, but unfortunately, his is not able to open my powerpoint files.  We tried saving the files to pdf, we still couldnt open them in corel draw. We're using version 12.

Pls help.

Thank you

Sheri Din