Gradient/feathering/Transparency ?

[dhj]

I'm using Web Designer MX Premium, learning to use the software, and I'm trying to do a banner merging a photo into the background, but don't seem to be able to do this very well. I remember doing this years ago using PaintShop Pro (ah that takes me back) but can't remember the process. I'm sure it is very straight forward but would really appreciate a pointer. I have attached a png of an example which I copied showing precisely what I'm trying to do (with a different picture and colours) The banner in this example is red and the castle picture is almost at the right hand edge of the banner - merged in.

Many thanks