Here's an example from my Intrepid hardpoint (since it only has one shuttle bay it's the shortest example)
ShuttleBay = App.HullProperty_Create("Shuttle Bay")
ShuttleBay.SetMaxCondition(4000.000000)
ShuttleBay.SetCritical(0)
ShuttleBay.SetTargetable(1)
ShuttleBay.SetPrimary(0)
ShuttleBay.SetPosition(0.000000, -1.400000, -0.086990)
ShuttleBay.SetPosition2D(65.000000, 106.000000)
ShuttleBay.SetRepairComplexity(2.000000)
ShuttleBay.SetDisabledPercentage(0.000000)
ShuttleBay.SetRadius(0.135000)
App.g_kModelPropertyManager.RegisterLocalTemplate(ShuttleBay)
#################################################
ShuttleBayOEP = App.ObjectEmitterProperty_Create("Shuttle Bay OEP")
ShuttleBayOEPForward = App.TGPoint3()
ShuttleBayOEPForward.SetXYZ(0.000000, -1.000000, 0.000000)
ShuttleBayOEPUp = App.TGPoint3()
ShuttleBayOEPUp.SetXYZ(0.000000, 0.000000, 1.000000)
ShuttleBayOEPRight = App.TGPoint3()
ShuttleBayOEPRight.SetXYZ(1.000000, 0.000000, 0.000000)
ShuttleBayOEP.SetOrientation(ShuttleBayOEPForward, ShuttleBayOEPUp, ShuttleBayOEPRight)
ShuttleBayOEPPosition = App.TGPoint3()
ShuttleBayOEPPosition.SetXYZ(-0.005075, -1.450000, -0.086990)
ShuttleBayOEP.SetPosition(ShuttleBayOEPPosition)
ShuttleBayOEP.SetEmittedObjectType(ShuttleBayOEP.OEP_SHUTTLE)
App.g_kModelPropertyManager.RegisterLocalTemplate(ShuttleBayOEP)
#################################################
You'll notice how it has the Shuttle Bay hull property, then the Shuttle Bay OEP. If you have more then one shuttle bay, you'll simply name them Shuttle Bay 1, Shuttle Bay 1 OEP, Shuttle Bay 2, Shuttle Bay 2 OEP, etc., in the same way that is shown above. You can create the carrier script in BCUT easily.
As KCS noted, make sure that the SetRadius portion of the Shuttle Bay property (not the OEP) is set to be slightly larger than the hull radius of the largest shuttle you plan to have your ship launch. For example, if you want your Galaxy X to be able to launch Danube's from it's main shuttle bay, you'll want to set the bay's radius to something like 0.250000, as the Danube's hull radius is 0.220000 by default.