Yes, you can use Query Analyzer and SQL Enterprise Manager to manage a server that is open to the Internet. I would consider making an exception at your firewall to allow that server to remain part of your NT domain, so that you can use NT Authentication instead of SQL Authentication.
I mean How can i find out the SQL Server on internet?
Sorry about confuse,
I dont have this kind of experience. Before i just install client software like
QA or Enterprise in my PC ,i can use this software manage my SQL Server on LAN.
Right now another SQL server on WAN ,i dont know can i use QA to find
SQL server or I have to get some remote software to log on remote server
and use remote server's QA?
When you are making the connection to the server in Query Analyzer, type either the server's name or IP address into the box labled SQL Server. Except for the lack of ability to enumerate remote servers (having Query Analyzer locate the SQL Servers and provide a list of them for you), the connection process is exactly the same as a "local" SQL Server.