Vlookup and forecast funtions

[vijaya]

There is data like this in excel:
Q C C C
A 10 100 110 150
B 20 300 330 370
C 30 200 220 150
D 40 700 777 900
A 50 50 55 60
B 60 2000 2200 3000
C 70 770 900 1000
E 80 80 10 88
F 30 222 333 100
A 50 123 532 254
C 60 25 35 45


I want to import some Item data and and Q from another excel file and place
it in 6 th and 7th columns. Next column I need to estimate the cost for the Q
that is in the 7th column using the data in the first 5 columns.
Like say, if some B, C and D are imported, I need to put a Vllokup function
and also a forecast function together, where using vlookup it will search all
the same B, or same C, or Same D items, and then puts the forecast function
for that data ..

Can it be done like this in any way