We have form letters that we send based on certain criteria. I would like to populate information in the form letter from an Excel file, but only for specified customers.

I would like to fill fields in a Word document from an Excel database (large spreadsheet). I want to enter a key field such as account# in the Word document, and have it find the matching line in Excel and fill into Word data from that line, customer name, address, ...

Ideas on how I can best achieve this result?

By setting up your document as a main merge document attached to your spreadsheet. See Mail Merge. You can tell Word to preview the merge and find your customer. You can have it search the data for a particular customer number.

You can print that preview. If you need to save it as a document, set the merge status to a normal word document. This unlinks you from the database and leaves the current data filled in.

If you want to do an actual merge, then you have to use the select recipients feature and check off who you want the merged documents to go to.