substr

Returns the substring of "string_expression" that starts at position "integer_expression1" for "integer_expression2" characters. The first character in "string_expression" is at position 1. If you omit "integer_expression2", returns the substring of "string_expression" that starts at position "integer_expression1" and ends at the end of "string_expression".

substr ( string_expression , integer_expression1 [ ,
 integer_expression2 ] )

substr ( [Sales (query)].[Sales staff].[Position code], 3 , 5 )