I'm trying to combine two different text functions (LEFT and MID) in a formula but can't get it to work.

The intention is to populate a 1 in a field (in a table) if an account number begins with 121 (the first 3 positions from the left) OR if the three digits beginning at position 23 in the middle of an account number are 000:

=IF(OR(LEFT(INDEX(Account_Item_Details.Account_Number,ROW()),3)="121"),(MID(INDEX(Account_Item_Details.Account_Number,ROW()),23,3)="000")1,0)

Account number structure:
000.00.00000.00000000.000.0000000.0000

Thank you for any assistance.