The regex you are probably looking for would be
"\b([fh]i|k)\w*(eld|ed)\b"
The \w*
should be equivalent to [a-zA-Z0-9_]*
, so that will allow any word-like characters be between requested strings.
The \b
is there to ensure, that the word really starts and ends with letters you want. Otherwise you might for example match string which contains word Unfailed
Also you need to remove $
and ^
from the regex because $
means end of line and ^
the beginning of line.