trying to create an (almost) circular formula between cells and data validated cells with lists

All on one worksheet, I have a bunch of data validated cells in multiple
columns and rows (ranging from B24 to K68) which pull from a master name
list in L2:L50. An exact match is not required, allowing me to type new
names in the data validated cells if the name I want isn't already on the
list.

What I'd like to do is put a formula in my unused list cells that reference
the range of data validated cells [and the names above itself in the list],
and if it finds a name that /is/ in the data validated cells but /isn't/ in
the list, show that value in the cell- essentially, so if I (or another
user) types in a new name, it also is automatically added to the main list
and is thereafter available in any of the other data validated cells/lists
without having to re-type it.

My brain hurts just thinking about it- so before I spend a lot of time, has
anyone else set something like this up, and if so, can you share what
approach you found most workable?

Thanks!!
Keith

--
The enclosed questions or comments are entirely mine and don't represent the
thoughts, views, or policy of my employer. Any errors or omissions are my
own.