Yes, it's to be done, even easy. You need to write a "script" with only one line such as:
set_focus(f)
where instead of 'f' you need to write appropriate value, which sets your camera to infinity. I don't know the correct value for you.
Load this script and set (in script parameters) option called simmilar to "Autostart". Then every time you run camera it'll run this script and set the focus to f.
It's possible, that you'll need to use also af_lock or something. However you have to just experiment, wheter above is enough;)