Found a solution to this:

First, you have to load the redir.lsp found here: C:\Program Files\Autodesk\AutoCAD XXXX\Express.

Then call its function.

Code:
(bns_redir path1 path2)
Example:
Code:
(load "REDIR")
(bns_redir  "//servername/Projects/" "C:/Users/username/Dropbox/Job Name/")
I just searched my ACAD dir for this lisp to find it out.