In answer to your subject, purchase Microsoft Word and install it.
I'm not sure what the content of your question is asking. If the software is some sort of add-on for Microsoft Word, you will need that. Also, while the program may be only compatible with Microsoft Word, it may only be compatible with the Windows version of MS Word.
So, before you set you trying to find an external CD reader, or another computer to use Remote Disk, see if the program will work with the Mac version of Word.
If you have confirmed all of that and are ready to install, see this info on Remote Disk (or get a USB CD/DVD reader).
Use the CD or DVD drive from another computer with your Mac - Apple Support
Use Remote Disc to Share a CD/DVD Drive Between Macs - OS X Daily