Try this, replacing 666 with the port number you want to use, 190.190.200.100 with the IP address you want, etc.:
Data Source=190.190.200.100MyInstance,666;Network Library=DBMSSOCN;Initial Catalog=myDataBase;User ID=myUsername;Password=myPassword;
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…