Otherwise we don't know what you're trying to match, or not match, with those wildcards.
Without any examples, we can't tell you why the wildcards you've tried don't match the filenames you expect them to work on, as we don't know what any of those filenames are.
Fileneame 01 = "21-11-02-EINGANG GV misterX.pdf" and
Fileneame 02 = "21-11-02-EINGANG GVin Restivo.pdf"
[for understanding: "GV" is the abbreviation for bailiff ("Gerichtsvollzieher") in German; "in" is the abbreviation for female; "Restivo" ist the name] => (Only) files with this the short "GV" or ''GVin" should be machted.
I tried also without success: *(G'V)*
and *(G'#V)*
But this file (filename) should not! be matched:
"21-11-02-EINGANG GvS - xyz.pdf"
Although I have now found another (temporary) solution with *(EINGANG G(Vin|V))*.
=> However, I would like to know why this does not work with the syntax'.
Furthermore I miss a syntax, with which one can indicate the search for a completely exact character sequence, with which also (1) the upper and lower caseas well as (2) the NUMBER of the indicated characters - completely AUTOMATIC(! ) are taken, so e.g. the instruction to DOPUS "Search EXACTLY the string WITH upper and lower case and also with the NUMBER of the indicated characters (so not only parts of a word will be found) with 'GV' or 'GVin'" with e.g. the (example)-command *{GV|GVin}* --- attention: {and } are only EXAMPLE-characters to signal to DOPUS that it should search ONLY EXACTLY for these characters (compare the exact requirements just now) in a file name ---, so that file names with for example characters "GVIN" or "GvS" or "agvbgvinc" are NOT matched.
I think you misread the wildcard documentation about the apostrophe escape character. It is for when you want to match a literal character that is also a wildcard character. If you want to match a # character you have to escape it as '#. That won't help with what you were trying to do.
If there's always a space before and after the GV or GVin then this would work:
*( GV | GVin )*
If the spaces are optional (i.e. the two words may appear right at the start of end of the filename) and there's always only one dot at the end which is the file extension, you could use something this:
(GV *|* GV *|* GV.*|GVin *|* GVin *|* GVin.*)
Or if GV or GVin might be the entire filename, with optional extension:
...Or you could use regular expressions instead of wildcards, which will make things a lot easier once you need to do something this complex. Those also let you specify min/max/exact number of matches as you want. So you probably want to be looking at regex, not wildcards. Most parts of Opus support both.