Excel / Database / Scripting Work

I currently have data in two Excel work books. The first spreadsheet (Master) is partially completed. I need someone to summarize data from the second worksheet (Details) to populate the remaining fields in the Master. For example, in Master there is a field for the ID 1234567 and a field that needs to be populated called Total. Need someone to write an Excel formula or macro to lookup all the rows in Details with the ID 1234567 and SUM all of the values in the Spend field. This SUM will then get input into the Total field for that row in Master. Make sense? There are about ten fields like this to automate. These are big spreadsheets! Master has about 90,000 rows and Details has about 500,000. Not sure if this can all be done in Excel (although it is preferred). Loading into SQL and using scripting to get the required results is also acceptable. I just need the output. Don't think it will take an expert more than a day. Please place a high bid if you are interested and I will send you the files via PMB. Then you can adjust your bid according to the work involved. Thanks.