Copyright Question

Is there a way to copyright or add in designed by................. to a spreadsheet that is unprotected? I have, with lots of help from excelforum, designed a couple of sheets but my boss insists on adding (c) KSAB which is not right. So I wonder if there is a way to copyright my work.

Thanks as always
Alan

i suspect if you have done this whilst employed,in their time. That they do own the rights to anything you create. Even if it was done outside work time but you introduced it at work without protecting it first it becomes the property of your company.