Zoom Image while maintaining frame size?

Hope someone can help.
I'm editing a holiday video and i have a scene where someone is taking a picture of a crab and I want to overlay the still image but I also want to slowly zoom into the still and have the frame size remain the same.
I'd also like the still to have a thin black border around it too.
How would I go about this?
I'm still running DR14 as i'd like to retain some consistency in my edit without the distractions of new features. I'm still learning.
Many thanks!
I'm editing a holiday video and i have a scene where someone is taking a picture of a crab and I want to overlay the still image but I also want to slowly zoom into the still and have the frame size remain the same.
I'd also like the still to have a thin black border around it too.
How would I go about this?
I'm still running DR14 as i'd like to retain some consistency in my edit without the distractions of new features. I'm still learning.
Many thanks!