Category: Text
Returns a specific number of characters from a text string starting at the position you specify
MID(text, start_num, num_chars)
Category: Logical
Specifies a logical test to perform
IF(Something is True, then do something, otherwise do something else)
Category: Information
Returns TRUE if the value is a number
ISNUMBER(value)
Category: Text
Returns the rightmost characters from a text value
RIGHT(text,[num_chars])
0
The formula examines the last digits that accompany the text string and then looks for the city code the precedes it.