Open a sample image, then put the desired watermark on it, then down where it says frames and history, lower right for me, click the history tab, then select the steps desired in the macro, then click the pic of the floppy disk in the lower right of that window to save as command

Then go file> batch process>select desired images of the same size as that one (or close to, the macro will put the watermark at the x/y coordinates on the image, so with varying sizes, it might be in different spots), then go through the steps.