Are you using a US or a UK model hub?
In either case, see the following list of buttons and remotes that have been demonstrated to work with smartthings. Each post will be labeled if it is available for the US, UK, or both. So you might find something else there if you don’t want to wait for a custom code solution.
Or if you do come up with a DTH that works for the Hank button, let us know, and we can add that to the FAQ as well. 