Excel 2007 : Grab data from model run data sheets

Hi,

So basically, I've only ever used Excel for basic stuff before (adding, averages etc etc)

Now I've been asked to create a sheet that will grab and manipulate data from sheets of model run data- before any of the data has arrived, so basically as soon as it does the results can be generated

The user needs to be able to type in the name of the spreadsheet, worksheet, and select a specific time for the data results to be chosen (It's a time step model)

The data for this specific sheet at this specific time then needs to be multiplied with data from another table.

How can I go about linking a user input to accessing data from another spreadsheet, and then using this data to do multiplications, without knowing specific cell references?

Any help would be very much appreciated!

I realise the above was rather waffly so let me know if you need any further info...!

Thanks

Ok, I managed to do pretty much everything I need to now. I just have one (hopefully a lot more straightforward!) query

my formula looks like this:

=INDIRECT("'["&$B$1&".xls]"&$B$3&"'!B"&$B$8)

It does everything I want, except change the column letter as I drag the corner of the formula box out to the right
(i.e. the B following the ! - I need this to increase to C,D,E etc as I drag it right)

Is there anything I can do to make it do this?

Thank you