An addition to the software for this device: there is a pogram that can be downloaded for the vendors websites. This, however, allows just changing the basic attenuation value and this is simpler if you do it with the five buttons.
Currently on Ebay there is a guy who wants to sell a software written in Python to control the attenuator (just look for ATT-6000 and Python). I am no expert in Python and, to be honest, that software seems to be a bit overprozed.
Third option: I found a software called PureBasic (see https://www.purebasic.com/). It reminds me of my old C64, HP-Basic and QBASIC times and it is simple enough for me to handle it, and strong enough to write a small control program for the attenuator.
A demo version limited to small programs (about 800 lines) is free of charge.
Holger 'Geri', DK8KW