File not found reported by fileinfo on Windows server 2019

My Ubuntu seems to think that “cmk” stands for cloudmonkey and does not recognize it as call to CheckMK.
The problem is that using both fileinfo as well as mk_filestats, to monitor presence of afile at the path starting with “C:\Program Files…” I get the alarm “File not found”, which is not true.
I am avare of a “bug” in DOS that the “DIR” command needs this path, as well as any other with spaces in it, to be written as C:\Program" "Files… to give the correct response, but I do not know which command Check MK uses to determine size and age of the file.
DIR is quite suitable, but with this flaw.

I have inserted full path in the field “File name”, but have still the “File not found”.

Where/how can I check the command the agent uses to check if the file does exist and how can I correct the syntax if wrong?