Need to adapt a dependent drop down box

[MichelleFisherTX]

I need help changing my data validation rules for the following issue:

In my company we have an excel document that helps price out items. Our items look like this: 1REM42
each cell is a drop down so you can change the item and get the general price of it.

EX: 1 R E M 4 2
I need to limit the third cell (c1 or the "E" in the example) so that when the first number (a1 or "1") is selected as a 1, only option "E" can be chosen when building the item.

All the cells already have their lists assigned in data validation. Unfortunately I cannot post an example without breaking company policy

[PaulM100]

You can post a mock up file does not contain the company's data in it. Make sure to include your desired results as well

[MichelleFisherTX]

I made a basic example of the problem I'm having. hopefully I uploaded it correctly.