Can not find PInvoke DLL SqlCeme35.dll?

Question

I am using Motorola device xr480 which does not have GUI.

When I try to access .sdf file in the device, i am getting the above error using the following code :

string Connection_String = @"Data Source=Application\RFID_FR_Data.sdf;Persist Security Info=False";
SqlCeConnection cn = new SqlCeConnection(Connection_String);

Please guide me to solve the issue.