Steam DLC Credit?

Is there a way i can get credit on steam for my DLC purchaces i mde from the positech website? I know its stupid since i can just reget them here, but is there a place on my order or recipet or such where i can actualy get a code to put into my steam?

If this is possible then I’d be interested as well. I purchased the base game via Steam and the DLCs via the site, but would like the download to be automatic on Steam after I reformat my PC or install GSB on another PC to do modding work. If any DLC gets patched then the automatic updates are simpler as well (nobody is perfect :wink: ).