Change this line
vConn = "Provider=SQLOLEDB;Data Source=Server;Initial Catalog=S;User ID=X;Password=Y"
to
vConn = "Provider=SQLOLEDB.1;Password=*****;Persist Security Info=True;User ID=sa;Data Source=111.111.11.111;Initial Catalog=master"
Here is connects to the database "master". Change that to the name of your database that contains the SP dbo.usp_adduser2