Tagging a Text File

I have various text files that need to be associated with various screens for call-up through a listbox. Is there a way to tag text files so that they can be listed with their appropriate screen? If not, what would be the most efficient method for searching the files text, let's say the first line, for a keyword to see if it is to be assigned to a particular screen or not? Thanks.

Seems to me that the filename or folder is a better way to do this, or a single file which lists all the others.