Custom commands to miniport driver in '98

Hi All,
This questiion is seen asked before, but I couldn’t find any satisfactory
replies.
My doubt is if we define custome CDBs and commands in our miniport
driver(Platform : 98), what are the possible ways to send that CDB to the
miniport. Definitely we can use ASPI for this. Let me know whether any other
solutions in the manner of filters, VxD, class drivers exist.
Is there anything like INT 21(for read/write sectors) that can be used for
this need?

Any help is highly appreciated.
Thanks in Advance,
Iqbal