I used to use HYPERSTR library for string processing routine. Now I use newer Delphi. I need to search a pattern in a string, for example the old function is function IsMa
Regular expression syntax is different. ? and * have different meanings. See http://www.regular-expressions.info/tutorial.html for an excellent introduction to regular expressions.
You would use something alike abcd[a-z]f or abcd\wf, or even other syntax, depending on what you would like to match.