VizLib Writeback Tool

Hello, 

I'm running into some issues with user variables and writing back to a QVD using the vizlib writeback function.  I am writing back to a QVD and I'm using a variable checkbox that the user can check if they have no changes to their form.  I'm using the variable bc I have the form fields uneditable if checked and if unchecked the form fields are editable again.  Anyway, if I have a user select the variable checkbox and then submit form, the audit column date does not update since there was technically no new data in the export.  Is there a way to update the audit date if a blank form is submitted, or is there a way to send a variable value to the export to trigger the audit date to update?