Using lookup objects fields in Formula in salesforce

Can i create a formula using a lookup object fields? For instance i have a custom object and got a lookup with account

i 开发者_StackOverflowneed a formula which uses a field from the account object

For eg.

 "PJ_"&SHORTNAME&"_"&UNIQUE-SEQ-NUM (UNIQUE)

Where shortname is a field in account object.. If using formaula is not possible is there anyway to achieve it?

Thanks

Prady

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Yes, if your lookup field in the custom object is called account, then you can traverse the relationship in your formula by using Account__r, e.g

"PJ_" & Account__r.Name

Will concat in the related accounts name value