RDA Pull error:Failure setting up a non parameterized query, possible incorrect SQL query

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C#

Greetings,
I'm trying to create a mobile application in C#, in which the data of a SQL SERVER table are "pull and push" to a PPC and back again.
I'm using .NET 2005, SQL SERVER 2005 and SQL SERVER2005CE.

Also, in the following code:

string sqlServerConnection = @"Provider =SQLOLEDB;Data Source
='192.χ.χ.χ';Initial Gatalog = Hospital_RDA;User Id=sa;Password=123";
SqlCeRemoteDataAccess myRDA = new SqlCeRemoteDataAccess("http://192.x.x.x/Hospital_PatientRDA/sqlcesa30.dll", "DataSource=\\Program Files\\pullmethod\\PullRDA.sdf");
myRDA.LocalConnectionString = "DataSource=\\Program Files\\pullmethod\\PullRDA.sdf";
string strDoctorEmployeeNo = txtDoctorEmployeeNo.Text;
string strCmd = "SELECT * FROM Patient WHERE DoctorEmployeeNo= "+ strDoctorEmployeeNo;
myRDA.Pull("Patient", strCmd,sqlServerConnection, RdaTrackOption.TrackingOffWithIndexes, "ErrorTable");

the following error appears:

Internal error: Failure setting up a non parameterized query, possible incorrect SQL query

The thing is, in SSMS the query runs successfully. Could anyone explain to me where I'm wrong?

Thanks