How do I use php rename across servers -

i need move file 1 server using php. proper syntax this? have tried has failed, yet know permissions correct. believe should like:

rename('//server1.host.com/folder/file.txt','//server2.host.com/folder/file.txt'); 

i trying on windows 2012 servers , have access everything.

the web server running code has file on it, i'm trying move file host.