I’ve just written a new midi filter Sysex Patcher.
Basically you give it two sys-ex patterns. One which decodes the incoming sysex and if it matches, uses the second pattern to generate a new sysex message. You use variables to pass arbitrary data from the decode pattern to the encode pattern. You can have have as many variables as you like (well up to 256) and you can name them what ever you like.
I’ve used $(a) and $(b) here to capture the two changing bytes.
I asked above if the data was fixed length. The above will work if it’s always two bytes of data you need to pass along. If you have a very limited range of data lengths you could hack it and setup a couple of filters. eg: say the data could be 2, 3 or 4 bytes in length you could do this:
Will this cover what you need? If so, let me know and I’ll include it in the next build.