Zend certified PHP/Magento developer

Create formula to combine different cells from multiple sheets by defining specific criteria

I have tried Google all the different combinations I can think of, but I am not experienced enough in Excel to know how to word this properly.

My issue is I have 25 sheets (one per employee) recording the billed amounts for up to 73 different projects (listed as my rows), with one column for each month of the year. Then I have a master sheet for the year where I want to write a formula that will record the overall value of each project, per month. Since the projects are not all listed in the same row for each sheet. Currently, the last person to handle this worksheet had input each specific cell by hand so my formula looks similar to this:

=’Employee1′!c2+’Employee2′!c14+…etc. (January)

=’Employee1′!d4+’Employee2′!d10+…etc. (February)

This is very time-consuming and as more projects are added, and certain employees only work on certain projects, what have you, I don’t have time to search each sheet and find which cell/row where each particular project is listed. I also need to do this and also filter for the month I want to consolidate?

Is there a way to search out one project by name, and then separate it by months?

Any suggestions would be a huge help and very appreciated!! Thank you in advance!