I can't find a 2014 download anywhere, and if you did find one, I would guess it wouldn't activate. You could also find the plugin folder and see if you can edit the "PackageContents.xml" file to include the version you are running. It all depends on the plug-in and the source files it uses and\or included with it.
Look for the SeriesMin and SeriesMax values
<RuntimeRequirements SupportPath="./Contents" OS="Win32|Win64" Platform="AutoCAD*|AutoCAD" SeriesMin="R18.2" SeriesMax="R22.0" />
Places to look for plug-in:
C:\Program Files\Autodesk\ApplicationPlugins
C:\Program Files (x86)\Autodesk\ApplicationPlugins
C:\Users\%username%\AppData\Roaming\Autodesk\ApplicationPlugins