Remove items from DV list once used, display elsewhere. Reset list when filling across.

Hi All,

Been searching the past couple of days to try and come up with a solution for this, and I'm getting closer.
Looks like the main component of what I want to do can be done using data validation and countif, but I keep confusing myself when trying to transpose it from the example spreadsheets to my own.
There's also a few other variables that will need to be considered. I think I know how I can deal with them though so they're not as important.

It's a quarterly schedule for utility meter readers, divided up into days across the top, and routes/areas down the side.
There's a space with each route for the employee ID to go, depending on who's doing it.
Down the bottom of the sheet, there's a few empty lines for all the available employees who haven't been allocated to a route.
On the second sheet labelled EMP LIST, is all the employee IDs. It's also got the areas they work- it's for something I want to implement later.

I can put all the employees into a single column list, then use basic DV to give a dropdown menu by each route, to assign an employee to it. This is pretty straight forward. I've also been playing with this in combination with a countif, so that employees already assigned do not appear in the list.
This is about as far as I've managed to get with it.

I need to get the employees who aren't assigned to anything to appear in a list below the routes. I'm fairly sure this is just another countif, but I'm not 100% on the exact formulas.
I also need the list in the dropdown menu to reset for each day of the quarter, i.e. if I assign an employee to a route on the 30th day of the quarter, their ID will disappear from the list for any other route for that day, but will still be there for the other days of the quarter.
So far the only way I've managed to do this is by duplicating the employee list for every day of the quarter, which is going to get very cluttered, and also makes staffing changes difficult. I'm hoping there's an easier way to do this using one data set.

I've added an example of the sheet. It's one week and it's only got about 1/3 of the routes we would actually have on any given day.
Any help would be much appreciated. If it can be done VBA-free, even better.

scheduledemo.xlsx

There is a very helpful guide on how to do this which can be found here:

http://www.contextures.on.ca/xlDataV...tml#listunused

I include a simplified version of your spreadsheet which will hopefully demonstrate how you might do it in your application.