Hi Anon4343,
It is not possible to directly add this column which shows the person who the workflow is currently assigned to. However, Microsoft provides custom solution and development support. So, you can post your question to the MSDN forums for a better response for custom solutions.
In addition, here are the links for your reference:
msdn.microsoft.com/.../hh147180.aspx
msdn.microsoft.com/.../gg153540
Thanks,
Jerry Cen