Remote connection to SQL Server Express fails

I have two computers that share the same Internet IP address. Using one of the computers, I can remotely connect to a SQL Server database on the other. Here is my connection string:

SqlConnection connection = new SqlConnection(@"Data Source=192.168.1.101\SQLEXPRESSNI,1433;Network Library=DBMSSOCN;Initial Catalog=FirstDB;Persist Security Info=True;User ID=username;Password=password;");

192.168.1.101 is the server, SQLEXPRESSNI is the SQL Server instance name, and FirstDB is the name of the database.

Now, I have another computer with a different Internet IP address. I want to connect to the server above using the third computer that does not belong to my local area network. I dont have access to that third computer at the moment, so I want to use (if possible) the client computer in LAN again.

SqlConnection connection = new SqlConnection(@"Data Source=SharedInternetIP\SQLEXPRESSNI,1433;Network Library=DBMSSOCN;Initial Catalog=FirstDB;Persist Security Info=True;User ID=username;Password=password;");

Does not work

Note that I am a beginner, so I am not quite sure what I am doing even though I know what I want to do. By passing the Internet IP to the SqlConnection object rather than the local IP address, how can I successfully connect to the server computer, using the client computer in the same network? Also note that my ultimate goal is to connect to the server with an external client, but I don't have access to that computer right now. I'开发者_Python百科d appreciate any help.

SQL Server Express doesn't allow remote connection by default.

• How to: Configure Express to accept remote connections
• How to configure SQL Server 2005 to allow remote connections
• Configuring SQL Server Express 2005 for Remote Access when SQL Server does not allow remote connections
• Enable Remote Connection on SQL Server 2008 Express

or just enter "enable sql server express remote connection" in Google or Bing and you'll get gazillion of answers....