Ah, thanks!
Somewhere I had read that inside square brackets some marks don't need to be escaped - except "!". However, I'm through the text, but I shall try again with the escaped period - maybe there were no matches with period and I didn't notice it.
The major problem had been in the "replace" sector: I had to replace everything manually, because all of my ideas concerning regex were inserted literally (no success
)
@DiapDealer: {Ll}: I don't understand neither the meaning of "L" or of the pipe. Which is their general function?