I've downloaded the .rpm file and tried to convert it into a .deb file. It's only for 32-bit system and i have a 64-bit system:
nomko@nomko-mint14 ~/Downloads $ sudo alien -d draftSight.rpm
[sudo] password for nomko:
Warning: Skipping conversion of scripts in package dassault-systemes-draftsight: postinst prerm
Warning: Use the --scripts parameter to include the scripts.
draftSight.rpm is for architecture i386 ; the package cannot be built on this system