Decrypt .fsd file

[AMO1]

I'm trying to mod the DMC1.
I was able to extract the textures, but I couldn't understand how the files with the extension fsd work.
It is also supposed to include the game's text.
Somehow I figured out where the text is located. I will upload a picture from the HX program that shows the place that is supposed to be text. There is supposed to be text written here that appears in the game:
(no password).

And here is the fsd file in case someone can figure out how to extract it.

r002fsd.rar