Did you ever find a solution to this?
I'm new to Windows, and I'm getting the same error you are when trying to load the plugin.
I downloaded glew32.dll and copied it to C:\System32, but that didn't fix the problem.
There are two users who are able to load the plugin, but I'm not sure what's different about their setup.
The spReticle.mll was downloaded as a compiled file if that makes a difference.
Here's the full error I'm getting:
loadPlugin "Z:/depot/tools/art_working/sww/win-amd64/maya/2016/plug-ins/spReticle.mll";
// Error: line 1: Unable to dynamically load : Z:/depot/tools/art_working/sww/win-amd64/maya/2016/plug-ins/spReticle.mll
The specified module could not be found.
//
# Error: pymel : Failed to get controlCommand list from spReticle #
# Error: pymel : Failed to get modelEditorCommand list from spReticle #
# Error: pymel : Failed to get command list from spReticle #
# Error: pymel : Failed to get constraintCommand list from spReticle #
# Error: pymel.core : Failed to get depend nodes list from spReticle #
// Error: line 1: The specified module could not be found.
(spReticle) //
Thanks for any help...