Codesets!

can I find&replace characters in files with non-Windows codeset & save them
as DOs-files using DOpus built-in commands or any external application?

Can i work with charsets at all (intresting in build-in options)?

Is there any "Finish section"-command or smth like this?

As in the contents of files, not the filenames?

Opus can't find & replace file contents at all. Try a text editor which does multi-file find & replace, e.g. TextPad or WildEdit.

If you mean the filenames then you can use the full Unicode character set when renaming.