external function GetScreenSpacePosition(node as NodeRef) as Vector3

I think that is what you are looking for

Also have these.

// Raycast in 3d using specified position/direction/distance

external function Raycast3D(origin as Vector3, direction as Vector3, excludedNodes as List of NodeRef, distance references Float, intercept references Vector3, meshName references String) as NodeRef of Class HBNode

external function Raycast3D_ListMeshes(origin as Vector3, direction as Vector3, excludedNodes as List of NodeRef, distance references Float, intercept references Vector3, meshNames references List of String) as NodeRef of Class HBNode

// Casts a ray from the camera in the direction near clip plane passing through the mouse position on it

external function RaycastMouse(excludedNodes as List of NodeRef, distance references Float, intercept references Vector3, meshName references String) as NodeRef of Class HBNode

external function RaycastMouse_ListMeshes(excludedNodes as List of NodeRef, distance references Float, intercept references Vector3, meshNames references List of String) as NodeRef of Class HBNode

// Casts a ray from the camera in the direction of the near clip plane passing through the specified xy position

external function RaycastFromScreen(x as Integer, y as Integer, excludedNodes as List of NodeRef, distance references Float, intercept references Vector3, meshName references String) as NodeRef of Class HBNode

external function RaycastFromScreen_ListMeshes(x as Integer, y as Integer, excludedNodes as List of NodeRef, distance references Float, intercept references Vector3, meshNames references List of String) as NodeRef of Class HBNode

// returns the worldspace origin, and unit vector direction, for a ray projected from the mouse position into the world

external function ProjectMouseToWorld(origin references Vector3, direction references Vector3)

// returns the worldspace origin, and unit vector direction, for a ray projected from the given screen coordinates into the world

external function ProjectScreenToWorld(x as Integer, y as Integer, origin references Vector3, direction references Vector3)

And there are a few others like this.