dbPA Batch Converter version: 14.4 (and 15beta) show the following behaviour:
Running Directory Opus Pro 10.5.2.1 (4934) x64 on Win 7 x64 as Explorer replacement. It offers shortcuts that open programs and target files, structured as:
"C:\Program Files (x86)\Illustrate\dBpoweramp\DMCFileSelector.exe" {filespath}
This opens dbPA DMCFS but not the selected file at {filespath}
However, "C:\Program Files (x86)\Illustrate\dBpoweramp\DMCFileSelector.exe" %1 works to open the intended file (*.Flac etc)

This seems to be a variance in dbPA more than DOpus as other programs work fine with the {filepath} command structure.
Murray