I know how to create a drop-down list in Excel using data validation but I'm trying to create one that lets me select multiple list items, takes the selected list items which are also separate tabs in the Excel document, and apply an adjacent value. Is there a way to do this in Excel?

Example:

I have a 10-tab document with the first tab being the Master, and tabs 1-10 behind it. I enter a dollar value in a cell, let's say $100, and then I select 5 of the list items (tabs) to equally divide that dollar value between them and such a value shows up in each tab corresponding with the five list values I selected.

So I have a list of 1-10, I enter $100 in a cell on the master tab, in the cell next to it, I select list items 1,3,5,6 and 8 (correspond with numbered tabs) to divide that $100 equally among the five of them. if I go to tab labeled "1", I see a $20 insertion as an outcome of five list items being selected divided by the number of items selected and applied as one of five outcomes to that specific tab.

Sorry for the confusion, hoping someone understands what I'm trying to do.