The EGR valve location on a 1999 Pontiac Grand Am SE with the Quad 4 engine isn't easily described with a single sentence because it's somewhat tucked away. It's generally located on the
intake manifold, towards the rear of the engine. You'll likely need to consult a repair manual or a detailed diagram specific to that year and engine for precise placement. A visual inspection with the engine bay clean will be your best bet. Be aware that you may need to remove some components for a clearer view.
Searching online for "1999 Pontiac Grand Am Quad 4 EGR valve location diagram" might yield helpful images.
