Yes you can; if the Data + Power cables can reach the DVD/CD player and the player can rest on a stable surface, you should have no problem.
If your case is a standard Tower, Mid tower or Mini tower (ATX-Matx) it should have a CD/DVD player bay but you may have to remove the metal plate that blocks the CD/DVD bay from being used.
Another possible solution is installing Windows 8 from a USB Pendrive. You only need:
1. Another computer at your disposal or,
2. Your own computer with the CD/DVD drive connected as you asked... just to quickly extract the Windows 8 DVD files to the Hard Drive in .ISO format.
3. An .ISO maker program.. most CD/DVD burners can create ISO files from CD/DVD disks
4. A program named Windows 8 USB Installer...