You can use the following wildcards for file or folder names:
The Asterisk “*”
The asterisk stands for any number of missing characters (even zero), that means e.g. searching for marc* may find the files marc, marc.png and marc_must_not_read_this.kwd. mar*.kwd may find marketplace.kwd and marc_must_not_read_this.kwd.
The Question Mark “?”
In contrast to the asterisk, the question mark stands for exactly one character, so mar? will find marc, but marc? will not find anything, as our files are called marc and marc.png. You can put as many question marks in the term as you want, it will find exactly that number of characters.
The Character Set “[...]”
This matches any of the characters between the braces.
Of course you can combine those two wildcard symbols in a search term.

Kfind does an exact search unless you used the applicable wildcards