VS Post-Build event creating file instead of copying folder contents

Question

There is a folder that gets brought in from a reference when I build and is created in my output directory, the path to it is "bin/debug/lib". For legacy purposes I need this folder to be copied to the following path "bin/lib".

I am using the following post-build event but it is creating a single "lib" file instead of copying the folder contents to a new folder called lib.

copy $(ProjectDir)$(OutDir)lib $(ProjectDir)bin\lib

EDIT

I managed to fix this issue by running MKDIR $(ProjectDir)bin\lib before the post-build event