Help copying the name assigned a phone number name anywhere in a spreadsheet to the next occurrance?

Hello,

Every month I take all the phone calls I've received - some have the name of the phone number next to them - some don't and add it as a new sheet to a spreadsheet. The workbook has two years worth of phone numbers and names.

Every month - phone number by phone number I do a find for that phone number in the spreadsheet and copy the name that I've assigned next to it in the past to the new occurrance for the current month. I'd love to create a formula that does this for me.

For example in the new sheet if the value of A4 is 818-555-1212 search through the workbook for the previous occurrence of that value that doesn't have a blank in the immediate column to the right of it and assign that value to the cell B4 in the latest spreadsheet. So if somewhere else in the workbook on a previous sheet it sees in A27 that 818-555-1212 has a B27 of Jane Doe it then copies that Jane Doe to B4 on the new spreadsheet.

I could add a blank column to the new spreadsheet so I don't overwrite any cells with the name already filled in.