It's a recently added feature of IMatch, in which, if I'm at file #878, in the file window, but file #15 is the one, that is actually selected, then there is a simple way to navigate to that selected file #15, which I can't remember. What is it? I'm sorry, that this may very well be documented. But, I did search the help, and couldn't find anything.
Goto... (https://www.photools.com/help/imatch/#fw_basics.htm?dl=h-54)
Also, remember how useful Bookmarks (https://www.photools.com/help/imatch/#fw_basics.htm?dl=h-53) are.