CREATE INDEX

I need to add an index to existing databases in the field.  I have
developed a utility that will execute a batch of SQL commands for me
and the following command is returning an error that says I need a
higher table level.  I understand the table levels so this is no big
deal but I was hoping there would be a SQL statement that I could use
so I don't have to develop a new utility just for this.  

CREATE DESCENDING INDEX sec_custd
ON "trans.db" (cust_id, "trans"."date", ticket_num)

- Bill