just added query path and formatted it correctly :
int pos1 = queuePath.IndexOf('\\');
int pos2 = queuePath.LastIndexOf('\\');
string qPath1 = queuePath.Insert((pos1 + 1), "\\");
string qPath = qPath1.Insert((pos2 + 1), "\\");
string queryString = String.Format("SELECT * FROM Win32_PerfFormattedData_msmq_MSMQQueue WHERE NAME ='{0}'", qPath);