SQL Server Replication Agent Permission Error messages:
  The schema script 'teste2_2.sch' could not be propagated to the subscriber. (Source: MSSQL_REPL, Error number: MSSQL_REPL-2147201001)
  
  The process could not read file 'C:\Program Files\Microsoft SQL Server\MSSQL10_50.VUZIQ_ENTP\MSSQL\ReplData\unc\ADSERVER$VUZIQ_ENTP_TESTE2_TESTE2\20130626155609\teste2_2.sch' due to OS error 3. (Source: MSSQL_REPL, Error number: MSSQL_REPL0)
  Get help: 
  


I have one sql from ip 199.168.***.*** working as Publication and another server 64.37.**.**. working as Subscription. The local Subscriptions of 199.168.***.*** is working fine but the external access from 64.37.**.** cant load file. 

How can I add a login for 64.37.**.** server to have read/write permission to 199.168.***.*** server ?
OS error 3 means path not found.  You must specify a UNC network share such as \\computername\snapshot rather than a local path when using pull subscriptions and/or a remote Distributor.  This is covered in Secure the Snapshot Folder.  I have also covered this in a blog post found here or here.

Also, ensure your replication agent process account has read permissions on the snapshot share.  This can be done by right-clicking on the snapshot folder -> Properties, and adding the user on the Security tab with Read permissions.

If you have any questions please let me know.