Is there a formula to search for a string in a formula (instead of the results)?

[timgaylord]

The attached is an example of a budget template. The budget templates are distributed to each Department Manager (Mgr). Each template contains department specific historical data and blank fields. Mgrs are expected to populate cells C7 thru D8. Column E is is a volatile column that is updated every month. If Mgrs use formulas that reference the cells in column E, their numbers will change un-expectedly with each monthly update.

I need to figure out how to either:
(A) Prevent Mgrs from entering formulas that reference the cells in column E
or
(B) Come up with a way to quickly and easily identify instances in which Mgrs have used references to Column E within columns C or D.
- I was hoping to be able to, essentially, dump in a formula that, if entered in F7 would check the formulas in C7 and D7 and report any improper references to E7.

Any ideas?