number of special character in string

i want to find how many special string like "-" in string?
for example
my filename is:
i want to find number of hyphen (-) in the filename
please help me
thank you

Please stop using the bold font. I don't need to yelled at to answer. I am not that old yet.

I once had a filter to find the folder depth.
So perhaps something like this would help:

It returns a value 1 too high

If you want to use it in a filter, try something like this:
"$add($len($regexp(%_filename%,'[^-]',)),1)" IS 3
to find 2 -

ok got it
i use this