If Command Extensions are enabled the PUSHD command accepts network paths in addition to the normal drive letter and path. ...

If Command Extensions are enabled the PUSHD command accepts network paths in addition to the normal drive letter and path. If a network path is specified, PUSHD will create a temporary drive letter that points to that specified network resource and then change the current drive and directory, using the newly defined drive letter.  Temporary drive letters are allocated from Z: on down, using the first unused drive letter found.