Apple Macintosh PowerBook 150 - Manual (Page 140)

Assigning Macintosh programs to DOS documents
Using the PC Exchange control panel, you can assign Macintosh application
programs to DOS documents. For example, you can specify that all DOS
documents whose filenames end with the suffix .XLS are to be opened in the
Macintosh program Microsoft Excel.
The following figure shows the PC Exchange control panel with some
assignments already created.
132 Appendix B
…as this type
of document.
DOS documents
whose names end
with this suffix…
…are to be opened
by this Macintosh
program…