Excel 2007 : Excel to record values on a weekly basis

First of all hi to all of you guys out there

Here is my problem -

I'm trying to keep track of all my earnings and expenditures in different currencies. I set up a sheet with all the bank accounts etc that I have and I record whatever I spend or earn. The accounts are in different currencies and hence to get a proper estimate in one primary currency that I use I got excel to pull the exchange rates from the Internet (that wasn't too hard even for an intermediate user).

Now the fun part starts - I want excel to get the total from one cell and record it on a separate sheet on a weekly basis. It is important that excel does it once a week and records the values in different cells every week as the currency xr are constantly changing. Say at the end of week 1 I want it record the value in B2, week 2 -> B3 etc. Do you think that can be done?

Please find the template I created attached.
The problem is in the MONIT sheet.

Thanks in advance for your help!

Cheers,

Bond002