add multiple child records based on parent criteria with formula url button

Thanks for the response, Mark!  The API format for the copy master detail help topic was a bit over my head, but I was able to figure out how to make this work by using the EditRecord and AddRecord API format.  I've created 25 different URL formula buttons (one for each product type) and I'm controlling which button the user will see using dynamic form rules.  Maybe not the easiest way to accomplish this, but it works!