I looked at that table in PHPMyAdmin - but I don't see where I can add a value. If I edit that table - ORDERID - there's a place for "Default" value, but what is that? something that will be appended to the number? I don't see any "auto increment value".
If I did it with a SQL command, what would that do - set the starting point? or is that what it would add to each order, so it would be order # 1000, then the next would be #2000 ?
You can also do this with an SQL command like this:
ALTER TABLE orders AUTO_INCREMENT = 1000;
If you change the auto increment initial value like this keep in mind the limit to this field will be 4294967295, not likely that you will reach this limit but it is something you should be aware of.