Create relationship between 2 queries and identify nulls

hi all,

I have 2 data sets - my "main" data set called Friends :

and the second one is Friends Birthdays: (note their is an intentional spelling mistake in Jeo's name :)-

In my model I have created a relationship between these two sets, based  on field "Friends". I would like to identify the fields that link up AND those who dont. So I'm thinking of creating a column in my Main table ("Friends") that 

1) contains the value of Birthday if there is a sucessful join AND

2) a string "No Corresponding record found" if the join returns a null.

1). Is there a simple way to do this other than creating a calculated/custom column?

2) otherwise - the code to populate a new calculated/custom for this operation.

Maybe I could Merge the 2 tables and somehow identify the columns? I'd need some assistance to do that.

Thanks

Much appreciated.