Is it possible to test if a cell is part of a named range?

Basically I have values that muct be the same across two or more sheets but need to be manually updated.

My idea is:

Using a worksheet_change event
First check if the cell is part of a named range,
If so check that it's value is the same as that in the other cells of the named range.
If not display a form showing all the both values and get the user to select the correct value.

I have never really worked with name ranges so not sure if it's possible. The bit I am currently stuck with is the first part (highlighted). If anyone could help it would be appreciated.