sysex filter ?

Hello

I own an old Roland keyboard (pre-GM) that cannot send RPN message.
But it can send short sysex messages when one moves some controls or push some
buttons.
Ex: cutoff control sends messages like this:
f0 41 0 3e 12 0 3 42 3b f7
("0 3" is the address of the Cutoff parameter, "42" is the value)

I would like to translate these sysex messages to RPN/NRPN messages.
Can minish do that ? (i'm affraid it cannot...)
Do you think it would be easy to add this feature to minish ?
(tips would be welcome ;)

Thanks in advance!

Xavier