Use Loop get the file-names/paths, save those paths in a variable, next you'd open the files from the variable you saved one by one with the Run command or COM or control-o in Word. Then do a control-f to call up the find window, and get the found and highlighted text with COM, compare it against the keywords you saved in a ini/tab-delimited file, again with Loop, then show a Gui with the options you found, and insert the selected one with Send or the Clipboard.
MS Office Automation Functions (via COM) [thanks Sean]
There might be a way to do the search via COM too, and not the find-dialog, so you could create an AHK Gui for that.
HTH