Here are some pointers.
Since you already know the intensity of pressure, you can directly feed that data into the intensity vs height data from inside Definitions > Wind Definitions. For details on how to do this, you may go to Help > About STAAD.Pro and browse to the section of the online help as marked below.
The software would then calculate the wind loading on the structure and you will be able to see these generated loads after you run the analysis.
When you say wind component on live load, do you mean wind load acting on the moving vehicles ? If so that is not something that you can generate automatically in STAAD.Pro. The software can generate moving loads on the structure automatically but any lateral load due to wind on the vehicles has to be added manually to the appropriate load cases.