Hi John,
Although I do not see that you have fully resolved your issue in this thread, an alternate way to perform IFC EXPORT can be accomplished using MicroStation key-in commands that could be used in: Function Keys, sequential MicroStation key-in script files (e.g. @C:\scripts\myscript.txt), MicroStation Batch Processor utility, or MicroStation VBA macros (CadInputQueue.SendKeyin). For a couple IFC EXPORT key-in workflows, please see: IFC - Batch processing
HTH,
Bob