Question: how to configure hllapi in qtp?
Answer: Start the emulator and connect to the server.
Go to Tools -> Options.
Select the Terminal Emulator tab.
Click <New/Modify> (<Open Wizard> for QTP 9.5 / UFT). ... 
Click <Next>.
Select the "Configure a new user-defined setting" radio button.
Enter in the name of your emulator.
Click <Next>.