I've searched all over the web and tried a zillion different programs, but nothing quite seems to do what I want.

I have a bunch (hundreds) of files that I would like to add a "comment" to, in the summary tab of the file properties.  As far as I can tell, the only way to access this is to right click-> properties-> summary -> and type in the comment (see screenshot).  I have tried selecting several files at once, but when you do this, the summary tab is all greyed out. 

Does anyone know of a way to edit several of these at once, or at least more quickly?  Even if I could just tab to the same field in the next item on the list, like you can in Windows Media Player (for example), that would be helpful. 

I messed around with recording a macro in DoOver, but I don't know how (or if it's possible) to make it generic, so that I could just select a file and hit a hot key that would go straight to the comments field.

Kind of like tagging, only for all files, not just music or photos.

Any suggestions?