Hi,

you can calculate what you need using circular references (in fact
circular references might be really useful, if you know how to use
them). I didn't study your formulas in detail, but maybe you will have
to rearange their position (means which is calculated first, second
....) to achieve result you expect.

Look for inspiration at Stephen Bullen's page:

http://www.oaltd.co.uk/Excel/Default.htm

(file Previous.zip).

Regards,
Ivan