PHP - How can I put a watermark in a Autocad DWG file?

I have a PHP Laravel application, and I need to insert a functionality to Insert a watermark (a stamp, better saying) from other file (another DWG, maybe) for a DWG file. I've researched a lot about it, and I haven't found any class or package for that, unfortunately. So is there another way (or trick) to do that? Perhaps convert and "reconvert" to some readible format.

Thank you in advance

P.S: Sorry about my English. That's not my native language

via Chebli Mohamed