Hello all and sorry for the poor title but I don't know how else to phrase it

I am having some excel problems, this might be a little hard to explain.

I am trying to attribute closed/won accounts to specific campaigns. For example, I have an account that is CW and I have the list of campaigns that contributed to that.

Company Close Date
Company A 2/1/2008
Company A 1/1/2009
Company B
Company C

then in another page in excel, I have that same company listed with all the campaigns.

Company Start Date Campaign Name
Company A 1/1/2008 In-person event
Company A 12/31/2008 Email Blast
Company A 1/1/2009 Email Blast
Company A 1/1/2010 Web-Seminar

I'm trying to figure out which campaigns attriuted to certain accounts. So for example,
we had two deals with Company A, one in 2008 and one in 2009. I want to say the deal in 2008 comes from the inperson even from 2008.

Sorry if this wasn't clear...it's very hard to describe. I haven't been able to get very far on this problem so if anybody could point me in the right direction (I'm thinking some kind of crazy array formula) I would gladly appreciate it.

Thank you.