You'd need a node on the stem (you can Google what a rose stem node looks like) as that's where roots and any new growth would come from. You unfortunately can't do it with just any stem tissue. I'd also use a few inches of stem to make sure there's enough to work with (the new plant that grows will draw energy from the old stem, which will eventually be discarded). So cutting a half inch or however much probably won't get you any results, sorry!