Trigger That Runs On Update

I'm new to SQL and am having some trouble figuring out Triggers. We use Microsoft Dynamics SL (formerly Solomon) for our accounting. We have a table that only has data in it while we're processing checks called PRCHECKTRAN. We'd like to build a report that uses the information in this table but it's only available until we "keep" the checks that we're printing. This creates an added step because we have to stop our Payroll process to go out and print the reports. It's been suggested to use a trigger to make a copy of the records in the PRCHECKTRAN table so we've got them after the checks are "kept." We're wanting something that's done behind the scenes so the user can continue to do things the way they always have while giving us access to the data past the payroll period.

Basically as soon as we calculate checks, PRCHECKTRAN is populated. Once the checks are accepted as good, PRCHECKTRAN is cleaned out. I think I need an update or insert trigger that copies all records over to another table that we'll create called something like PRCHECKTRAN_HOLD. I'm just not familiar enough with SQL to write it. Any direction you can provide would be greatly appreciated. Thanks.