How can I open *.ext files ?

Hi!
Thank you for your help ! :up:
I will try to explain to you what kind of maps they are the best way I can (I don't know how to translate the exact words in english)
Well, they show as diagramms (lines) how the earth looks with the heights of moutains on it and how much big the valleys are for example. They are used by political engineers or architectures. I believe that every country is digitalised (designed) this way. They are in a 1:5000 scale.
Can you give it a try?

Hi
I got them from a colleague at work when we were working together in a photometry lab. Now I'm working in a political engineers' office and it would be very helpful if we had these maps
The problem is that maybe it was the "software pack" that was in his PC that made them work. As I can recall there was Oracle too.
I tried opened them with ArcGIS but it didn't work as it didn't work with AutoCad too.
The problem is that looking in the Internet I couldn't find any proper programm.
Why is that? At least I should be able to find something ...

I have the original maps but I believe that if I manage to find the same programs that I used to work with, I will open them.
I asked my college proffessor and he thinks the same.