input mask for column of email addresses with same domain name

Hello,
I hope someone can help me! I am entering contact information in a spreadsheet. One column is for email addresses. Every email address has the same domain name. I am tired of typing "@blahblahblah" over and over, and I'd like to make an input mask for this column that will allow me to simply type the beginning of the address. This sheet will eventually have about 2000 rows, and this would save 15 keystrokes per row. ! Any suggestions?
Thanks for your help!
Va

Maybe =A1 & ""@blahblahblah"

Hooray!! Thanks! I think I can make that work!