The first thought that comes to mind is using a USB flash-drive that can be password-protected. This company claims its password-protection software is free: [
^], but I have never used it.
This CP article may be helpful as a starting point: "Developing a USB Storage Device Protection Tool with C# By Ozcan ILIKHAN | 5 Jun 2009:" [
^].
But, it does show techniques for write-protecting all USB drives, not a specific one.
See discussion here: [
^] for other ideas. And discussions on SO here:[
^].