Adding a custom property with no value

 Hello,

I am working on a task where the Solidworks PDM data cards are not syncing up with the file properties. We believe this is because of a mismatch of Custom Properties since the files were downloaded from supplier websites. I'm trying to find a way to add the Custom Properties from the Task Scheduler, but when I do it changes the data cards as well, which we do not want because the information in those is accurate.

 

Is there a way to map the info from the data cards to the file properties instead of the other way around? Failing that, is there a way to create a custom property using the task scheduler that does not have a value? Every time I try to do that it will not let me start the task.