Moving text out of the source file

Question

This may be a basic issue, but I did not find a way to implement.

In my C# source files I have several text messages.
I know from other compilers that such texts can (and should) be moved out of the source and be saved in a text file, where they can be edited.

The C# Localization property option enables to change control names by local language, but I don't know how I can do it for text messages.

I would best like to have a command that will automatically or manually move out all embedded text to an indexed text file.

How can that be done??
Thanks