This _could_ be done, but will require hand coding to accomplish, and is not supported.
you would need to add the checkbox to the repeat region in the results page, and use the ID column from the recordset as the checked value.
for the checkbox name, use "[]" at the end to create an array of the checked values:
name="checked[]"
you would then need to create a loop through the checked values and perform an update for each id in the checkbox array to update the status column to completed.