STR: Return a subset of the string

Use the STR formula function in a situation, query, view filter or table view threshold to start searching for the value in the text or time stamp at a specific character position.

STR function Return a subset of the string
Searches for a value occurring at a specific location in the data returned by the attribute. When you select STR, a Substring Comparison Information window opens for you to enter the starting position, such as 4 for the fourth character from the left to begin looking for the value.
Text example
This formula looks for ar starting with the second character in returned values for Handle of the User, so aardvark, parrot and sardine meet the comparison, but not artist, star or SARDINE (case-sensitive). 
STR(Handle of the User) == 2,ar
Time example
This formula begins looking at the seventh character, the year, to find 10, so a timestamp of 07/12/10 09:29:05 would meet the criteria but 10/11/09 11:07:05 would not.
STR(Timestamp) == 7,10
Wildcards
You can use an * asterisk wildcard to begin or end the attribute value. You can also use the ? question mark wildcard for a single character at that position.