Hi, You can do two things. First you can use the "compass" display(The one that's next to the PFD. Sorry don't know the real word for it.) and press the APT button on the control panel above it. Or go in to for instance the default 737s panel.cfg go down until you see something like this
THIS ONE WILL NOT WORK IN FS2002
,but it will work in 2004.
And put that in the PMDGs panel.cfg. If you do this you will have to go to VIEWS on the top menu , INSTRUMENT PANEL then click on GPS. And it should work.