'.*?'

IF @RetValue = 'Cat'
   /*SET @RetValue = 'WrongLocation
and it works here' */
   ------testing line
SET @Dude = 'Punto'
/* comments */
    -- But it doesn't work here because inside comments!
    -- and this is aren't the end
    SET @RetValue = 'But this should
work here'

'Cat'
''Punto'
and
'But this should
work here'

string commentFree = Regex.Replace(sourceString, @"/*.*?*/|--[^n]*n", string.Empty, RegexOptions.Multiline | RegexOptions.Singleline);