instr

Searches "string_expression1" starting at position "integer_expression1" for the "integer_expression2" occurrence of "string_expression2". If "integer_expression1" is negative then the search is backwards from the end of "string_expression1". Returns an integer indicating the position of "string_expression2".

instr ( string_expression1 , string_expression2 [ , 
integer_expression1 [ , integer_expression2 ] ] )