Certain number determining another fields data..??????? Help

[Moderation]

Hello i'm unsure how to explain this at best.

I have a table with Area code say, 4302 and that 4302 relates to another field that is suburbs, so 4032 = Yellowvale

How can i make a validation rule to say when one of these suburb codes is entered, in the other field the suburb affiliated with that code is shown?

Thank you, im very new to access so apologies.

[zmbd]

Moderation,
I would avoid the validation rules if possible here, they can get messing, instead, this essentially the same question as asked here (https://bytes.com/topic/access/answe...ata-validation); therefor, I suggest the same methodology.

-z