Dear Brianwarnock,
Thank you for pointing out the difference between blank and empty cells.
The data I got contains empty cells, so the formula received from Kiwiman works perfectly: =IF($B2="","",IF($A2<>999,"0"&LEFT($B2,1)&" "&MID($B2,2,4)&" "&RIGHT($B2,4),$B2))
Thanks again,
Irmgard Wesselbaum