Increment numbers inside a string
Perhaps you can work around with something like that:
A1: "user"
B1: 1
C1: "@example.com"
D1: =$A$1&TEXT(B1,"000")&$C$1
[Edit: This applies for the english version of Excel, otherwise the last line should read =$A$1&TEXT(B1;"000")&$C$1, note the semicolon instead of a comma. Thanks @Kevin for clarifiying this point.]
Then you can drag-and-click column B and D, where D will look like
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
...
Better use the below. This doesn't require to create a extra column with incremental values. If you follow the previous extra column(A1) then finally you have to remove that column and created values to be Copy & pasted (as values) again.
="user"&TEXT(ROW(), "000")&"@example.com"
="user"&TEXT(ROW()+100, "000")&"@example.com"