VS 2010 Make right-click equivalent to clicking left then right

I am working on a WYSIWYG HTML editor using a Webbrowser control. I'm working on ways to edit objects/elements (images in particular) after they have been added to the control. I want a right-click to bring up properties - spacing, border width, border colour etc) which can be modified. I have added a mousedown event to the webbrowser control. The problem is that right-clicking (say) an image, does not select the image, as left-clicking would do, so it's hard to work out which object has been clicked. If I left-click first (to select the image), then right-click, I can work out the rest.

Is there an easy way to make a right-click behave as if the user had left-clicked, then right-clicked?

Thanks.