For instance, aol, cs.com, and compuserve.com email domains. I want those values in the Excel column automatically erased and am wondering how do you do this?

Do you mean eveything behind and including the @ ?

Ctrl + H
Replace what @*
With ( leave blank)

Replace All - OK

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Sjeff, maybe it'd be clearer if you give an example. Let me guess: You have a column of email addresses in a spreadsheet, all using the format "abc@aol.com", "def@gmail.com", "ghi@att.net" and so on; and you want some formula you can use to create another column saying simply "abc", "def", "ghi" and so forth?