I assumed Purpose to Remotly access SQL Server through any application.. Like VB6 or .NET
You can Create a connection string in aaplication (Remote Side Application)
For example in vb6.0 application you can create like this..
If Con.State = 1 Then
Else
Con.Open _
"Provider = sqloledb;" & _
"Data Source=ServerIP;" & _
"Initial Catalog=DatabaseName;" & _
"User ID=UserName;" & _
"Password=Password;"
End If
for "ServerIP" you can use your Internet_Service_Provider's IP.
Hope it will help.