It is unfortunately not possible.
However, you may try to send the commands from your micro in a manner that "parity".
For example, to send a command to the motor, the "!" which is Hex 21, already has an even number of bits, so you can send as is.
The "^" is Hex 5E is 0101 1110, has an odd number of bits. So you would send 1101 1110 instead.
There are only a handful of commands like these to figure out once and plug in your program.
The only tricky part will be the numerical commands which are hex numbers from 0 to F. You may need to create a small lookup table to do the conversion.
The receiving part it much easier. All you need to do is to mask the Most Significan Bit by doing an And with a mask of Hex 7F.