Okay did a bit more research
fxDTSBrick::AddEvent(%this, %enabled, %delay, %inputEvent, %target, %outputEvent, %par1, etc...);
calls
serverCmdAddEvent(%client,%enabled,%inputEventIdx,%delay,%targetIdx,%namedTargetNameIdx,%outputEventIdx,%par1,%par2,%par3,%par4,%par5,%par6,%par7,%par8,%par9,%par10,%par11,%par12,%par13);
They seem to both use a different set of parameters.
Still not sure how fxDTSBrick::AddEvent() actually uses the named brick feature for target though