Hundred videos just with a different head and tail

When we surf on youtube, is not rare to discover that coupon companies are automatically building a video for each coupon or that some hotel portals are automatically generating videos from them photos/maps and other infos.
Ok, I don't want to automatic generate videos, but I would need to create my video and create a custom version (just changing the head and the tail) for every country.
Do it by hand take a big time! How to do it trough some software and not need to rent a developer?

I would say create a After Effects template and use it over and over again.

Once you got the template you have the "Replace footage with > File" function..

In other words if you need to change a country flag image for example you can do that within seconds.
Once changed you add it to your render queue and create the next one. Once all done you render the shit out of them.