I have 12 workbooks one for each month with 30-31 sheets in each for each day. We use these to track our calls for service for the fire department. On January 1 we start with call 01 and each row is an additional number, each day we start from the last run from the previous day, and each month starts from the last run of the previous month. I am limited to staying with the current format that we are using. Current these run number are entered manually and occasionally get entered incorrectly and we have to go back and fix a couple hundred. I am looking to have these auto number based on the run before, page before, work book before.