I need to add text to multiple existing cells

[dpierce8657]

Hi, I have an existing spreadsheet listing users for my customer.  I need to insert an email suffix to the existing extension number in each cell:  Example:

Existing cell contains: 1701

I need to add: "@xyzcompany.com" to the end of the existing extension number, so

The result would be: "1701@xyzcompany.com"

There are 478 extension numbers listed in my sheet.  I need to add "@xyzcompany.com" to each.  Any advice you can provide is greatly appreciated.  I'm using Windows10 OS on my PC, and the version of Excel is:  

Thanks!

[#2]

@dpierce8657 Suppose the text "1701" is in A1, enter =A1&"@xyzcompany.com" in B1 and copy down as far as needed.