Bruce - I moved this to the Calibre community since this is a Calibre related question and it will receive better visibility. That for your participation.
You can use MGC_CALIBRE_DRC_RUNSET_FILE, MGC_CALIBRE_PEX_RUNSET_FILE, or MGC_CALIBRE_LVS_RUNSET_FILE to specify a runset that Calibre Interactive loads automatically when it starts.
The environment variables with LIST in them (MGC_CALIBRE_DRC_RUNSET_LIST, MGC_CALIBRE_PEX_RUNSET_LIST, and MGC_CALIBRE_LVS_RUNSET_LIST) are used to populate the Load Runset File dialog box. To use the *LIST environment variables, create a text file with the list of runsets, one runset per line, and define the *LIST environment variable to point to the text file with the list.
The *LIST settings take precedence over the *FILE environment variables, so if you have both defined, you'll just get the Load Runset File dialog box populated.
I hope this helps,
Thanks a lot for your great help. Indeed, you are right. I was trying to load a file with a MGC_CALIBRE_DRC_RUNSET_LIST