create command button for data entry

I want to create a query logging system (query being a question asked by a customer who calls in)

I want to be able to capture each customer's questions in a table, but I do not want to over-write the previous question asked by that same customer - I want to be able to keep a log of all the questions asked so that I would be able to track whether the customer's questions have been attended to and the query closed (similar to a help-desk ticket system)

The customers already exist in the database, so there details are already in the system.

I want to do all of the above by clicking on a command button on a capture form.

Thank you.