Rcook99 they this:
To associate a file type with CorelDRAW
1. Click Tools Options.
2. In the list of categories, double-click Global, and click Filters.
3. Click Associate.
4. In the Associated file extensions with CorelDRAW list, enable the check box of the file type you want to associate
and check this
To break a CorelDRAW file type association
1. Click Tools Options.
2. In the list of categories, double-click Global, and click Filters.
3. Click Associate.
4. In the Associated file extensions with CorelDRAW list, disable the check box of the file type association you want to break.