Start A Batch File At A Specified Time

I’m converting from Excel to LO CALC. My Excel routine calculates a specific start time each day to start a batch file. Excel then starts the batch file at the calculated time. Initiating the batch file is via the Excel’s Application.OnTime feature.

I’ve got CALC to calculate the start time. I’ve tried to then start the batch file with something like Application.OnTime Now(), MyFile.bat. The batch file actually starts but I get an error “BASIC runtime error. Variable not set”. What I need to learn is how to pass the calculated start time to trigger the batch file. Is the use of Application.OnTime just the wrong way to go? Is there some other approach that works in CALC?