Flash MX 2004.
item.linkageExportInFirstFrame
Property; a Boolean value. If true, the item is exported in the first frame; if false, the item is exported in the frame of the first instance. If the item does not appear on the Stage, it isn’t exported. This property can be set to true only when item.linkageExportForAS and/or item.linkageExportForRS are set to true.
The following example specifies that the specified library item is exported in the first frame:
fl.getDocumentDOM().library.items[0].linkageExportInFirstFrame = true;