How to avoid the Mutating Triggers ??

Dear Master,
I've some problem with this situation.
It's hard to explain what kind of
problem is, but i try to tell you
with my limitation on english.

How do I "recalculate" one of
my field, if i updated one of
the record that's have position
in the middle of all record.
Here my Ilustration is;
----------------------------------------
Poin-|FdDate | Code| IN |OUT| Qty |
ter. |----------------------------------
1 |01/01/2003 | 001 | 5 | 0 | 5 |
2 |01/02/2003 | 001 | 3 | 0 | 8 |
3 |01/03/2003 | 001 | 0 | 1 | 7 |
4 |01/06/2003 | 001 | 100 | 0 | 117 |
5 |00107/2003 | 001 | 0 | 1 | 118 |
6 |00108/2003 | 001 | 0 | 1 | 119 |
7 |00109/2003 | 001 | 0 | 1 | 120 |
----------------------------------------
And what i want is, update the record
on Pointer no 4. on "IN" is changed from
100 to 10 And Qty is Automaticly change
from 117 to 17. like this;
----------------------------------------
Poin-|FdDate | Code| IN |OUT| Qty |
ter. |----------------------------------
4 |01/06/2003 | 001 | 10 | 0 | 17 |
----------------------------------------
Following with record below it, and become
like this;
----------------------------------------
Poin-|FdDate | Code| IN |OUT| Qty |
ter. |----------------------------------
5 |00107/2003 | 001 | 0 | 1 | 18 |
6 |00108/2003 | 001 | 0 | 1 | 19 |
7 |00109/2003 | 001 | 0 | 1 | 20 |
----------------------------------------

I've been trying using cursor inside of
my trigger, It didn't work and it's
"mutating". i thought my trigger is
working recursive. It's very Urgent
for me. I've been migrating Database
from Ms-SQL, so far so great, till
this Problem I've been spending my
3 Days with No-Result.
It's time to Give-up.
So gimme your hand please...???

Thank's to you and,
GOD Bless You All.

Yudha Setiawan.
VoIP
No. : 628899911223344