URGENT: Using function inside query

I need some help on the following problem. I have an account info
table that has a hierarchy of accounts. The grouping goes from end
user to organization to reseller. I have a PL/SQL function written
that gives me the tree, so I just whittle it down by selecting the one
id for a reseller:

select account_id from roll_account(1186) where hierarchy_type_id = 2

The problem is I have data like this:

account id name

1 Company A
2 Company B
3 Company C
4 Person 1 (in Company A)
5 Person 2 (in Company A)

If I pass it the number of let's say Person 2 -- the above query wold
give me the account id of 1. How can I do a query using that
function so that it automatically inserts the account_id to show the
"rolled up" account id ?

Bradley Miller
NUVIO CORPORATION
Phone: 816-444-4422 ext. 6757
Fax: 913-498-1810
http://www.nuvio.com
bmiller(at)nuvio(dot)com