After creating a custom property in toolbox and assigning a value to it, I exported the component's data to excel. The custom property appears in the excel spreadsheet with the value the same for each item (each row). I then add a formula to each row in the custom properties column. The value updates correctly. I then go back into "Toolbox" and import the new data. The custom property updated correctly for each row. I saved, then exited Toolbox. Upon re-entering Toolbox, the custom property was replaced with the original data that I had entered.
How do I keep my data from being overwritten?