> Writing the declare statements for the functions from ibase.h is
> straight forward in most cases. But, VB cannot call functions declared
> as "ISC_EXPORT_VARARG" since there is no option to select "cdecl"
> calling convention - VB does require stdcall conventions. For this
> reason you presumably cannot write an Firebird-Driver in VB language,
> since "isc_start_transaction" is a VARARG function.

If calling convention is the only problem, then just use
isc_start_multiple()
instead of isc_start_transaction.

Ivan
http://www.volny.cz/iprenosil/interbase/