Help with sysexin data processing (newbie)

Hello all,
first time user and got stuck. I have a patch which receives Midi sysex from a host via the "sysexin" object. Now, the sysex messages are all 22 bytes long, and each contain a unique header (the first 5 bytes). There are 3 types of unique headers, hence type of messages. I am trying to send each to its own LCD screen for display. Since the "sysexin" object receives everything that comes in without distinction, I am trying to figure out if it is possible with creative use of the zl object, to route these messages based on their header type. What I have right now after the "sysexin" is a "zl group" object which creates lists of 22 (the length of each full sysex message) but I need after that a way to inspect the list, and use the 3 headers (each comprised of 5 bytes, which I know), to route each type of message to its proper LCD display.
Hopefully this is somewhat clear. Would appreciate any help.
Cheers.