In order to use the mentioned object in your program, you need to include the Header file of TDxJoystick in your current CPP file. This can be done using the following syntax : #include "theHeaderfile.h" where theHeaderFile is the name of the TDxJoystick header file. If the file isn't in the same directory as your application, you need to use : #include "c:\ ..\include\yourFile.h". To be noticed that you need to input your path to the file in the mentioned syntax. For more information about this issue, check the following support website.