how to convert .txt to .snp ?

I need to import s-file(.snp) into Ansoft Designer. But my s data is in .txt format. How can i convert it?

just rename the file extension

Thank you, it works right now.
The weird thing is that "changing the extension" is what i tried before. But what happened by that time was *.txt --> *.s2p.txt ....
So i cannot delete the .txt by that time and i don't know why it works this time, either...

So tiny issue, but cost me several days

To change the pre-fix you can open a DOS window and type
>rename ?.txt ?.snp

Assuming you in the directory that the file is in.

Cheers

Thx a lot!
Ur reply is a "general solu."...
:D