I think I found an excellent way to create this monitor. I found that if we call these apps by passing all of the pieces at once, the application works fine. After digging a bit, I was able to find ways to embed all of the special characters that are needed for a request to the application into the Send field in a custom TCP monitor:
https://support.f5.com/kb/en-us/solutions/public/4000/100/sol4186.html
However, I ran into a wall that I don't know if I can scale. The send string includes ASCII null chars. These should be able to be escaped as:
\x00
However, it seems the BIG-IP web interface doesn't allow these chars. For, I got an error when trying to add the custom monitor (see attachment). Is there some other way to get these into the system?