Searching through vlookup for multipal criteria returning results in drop down list

Hi,

Hopefully someone can help, I know what I want to achieve but I dont know how to achieve it. Basically I have a spreadsheet with several coumns, date, supplier, description, quantity, order number and cost etc; all the information in the columns are entered apart from the 'cost' column I want the cost column to search the other tabs 'A,B,C... -Z' for the cost using the data from the other columns i.e mainly supplier, description and order number but because the descriptions do not fully link and not exactly the same I wouldnt mind a drop down box listing all the items under that order number so I can select the exact cost.

I have tried to attached an example spreadsheet

Hope that helps and someone can help me...

Using Excel 2010.