BioSnapOn Addon

I use a software called BioSnapOn to automate login forms with fingerprints.
It will set focus to a specified window and send username/password keystrokes upon successful fingerprint scan.
But it lacks a way to programmatically set focus to the correct input field.
So, if focus is shifted between login-window opening and BioSnapOn executing, the login will fail.

What it does offer is "prefix" keystroke(s) that will be sent before credentials.

So i need a software that can be launched by a shortcut key and does 3 steps:
1.
set focus to a specified window
2.
within that window set focus to a specified input field
3.
mark it's content if it has any.

Without cost-considerations, ideally this program would be a small standalone executable.
To avoid config UI: If delivered with source and compile-instructions, the shortcut key, window- and input- names could be hardcoded.
If not a standalone executable, it could also be a script that needs a runtime, something like autohotkey.
Would maybe be more practical as no config UI and no compile would be needed.