Yes, but you’ll need to load a different program on the H90 every time you want to have it change the channel on your amp.
On the H90, set MIDI output mode to Transmit, and you may need to set PC offset to 1 depending on how the PC messages work on the Mesa. Connect a MIDI cable from the H90 MIDI output to the Mesa MIDI input.
You will then need to configure the Mesa so when it receives certain PC messages, it will use the correct amp channel for that H90 Program.
Let me know if that helps.