Hello,

If your data is in Sheet1 in cells A2:M1001 (account names in column
A, Jan data in column B, Feb data in C, ..., December data in M), then
enter into Sheet2:
Cell C1:
1 for January (2 for February, ..., 12 for December)

Cell A2:
=COUNTIF(INDEX(Sheet1!$B$2:$M$1001,,$C$1),""&INDE X(Sheet1!B2:M2,,$C
$1))+COUNTIF(INDEX(Sheet1!$B$2:M2,,$C$1),INDEX(She et1!B2:M2,,$C$1))
Cell B2:
=INDEX(Sheet1!$A$2:$A$1001,MATCH(ROW()-1,$A$2:$A$1001,0))
Cell C2:
=INDEX(INDEX(Sheet1!$B$2:$M$1001,,$C$1),MATCH(ROW( )-1,$A$2:$A$1001,0))

Now copy A2:C2 down to row 1001.

This flexible approach is taking care about your data arrangements, it
is about 5x faster than the /10^10 one given by Biff, and it can even
sort text (not necessary here, but you might need it one day).

See http://sulprobil.com/html/sorting.html, please.

Regards,
Bernd