1). If you search the selected library, you should type the value in main window (such as NE555), and NE555 will show NE555XXX components as well. You don't need to know exact number.
i dont know maybe i did it incorrectly. but i tried in diptrace bundled standard library where a bunch of soic connectors and names etc. typing "soic" wont direct me to anywhere.
2). For wildcard search through all libraries use Objects/Find Component option
thanks now i know the mechanism.
thinking about it... if its too hard to implement pattern search (eg *555?-ETC) then "simple keyword search" is sufficiently "good enough" search engine. ie suggestion, by typing "555" in the search textbox (top of the library view on the left corner), the library will automatically show (filter) only parts with "555" in it (regardless if its in the beginnning, middle or end of part number), and automatically, no need to click that "dormant" binocular button. empty'ing the textboxt will return to normal "view all" parts.