Inject / Overlay an MFC window into an existing application

Well, that is not exactly an "overlay", what you are seeing in the image is an Outlook plugin in action. There's a well-defined interface for these plugins. See the examples at

http://www.codeproject.com/com/Outlook-addin.asp ("Extending Outlook with new features")
http://www.codeproject.com/com/OutlookForms.asp ("A VC++ Outlook COM Add-in that publicizes a custom form")
http://www.codeproject.com/useritems/Capture_Outlook_event_vc6.asp ("How to Create Outlook AddIN / Plugin")

on how to do that.

Hi jkr,

You are right they are using an Outlook plugin to perform this I am too (I should have mentioned that).
I looked up the custom forms and to my surprise they seem to be using that for certain display views like the one seen in my screen shot.

But there must be a bit more to it, because for example LinkedIn insert their views with rollover events and transparencies (see link)
http://img221.imageshack.us/img221/392/winspylinkedinwindowey5.jpg

Are they just using the form or are they also injecting their own custom windows into the mix.
Thats the main reason why I wanted to know of techniques to inject my own windows and overlay over  the application controls. But if all theses functionnalities exist in the custom forms that would be great !

I will look into this and get back to you with the points.
Christian

Thanks I think I will be able to work with the last solution.
Just need to work some kinks out.

Thanks jkr