I'll try.

tblRawData
RDID Raw_Data
1 @S1
2 A02F
3 A12F
4 A22F
5 @TPO
6 @TPC

SELECT Raw_Data, (SELECT Count(A.Raw_Data) FROM tblRawData AS A WHERE
A.RDID <= tblRawData.RDID AND Left([Raw_Data], 1) = "@") AS Tag FROM
tblRawData;

When the query is at tblRawData.RDID = 1 you get:

@S1, (SELECT Count(Raw_Data) FROM tblRawData WHERE RDID <= 1 AND
Left([Raw_Data], 1) = "@") AS Tag
= @S1, 1

When tblRawData.RDID = 2 you get:

A02F, (SELECT Count(Raw_Data) FROM tblRawData WHERE RDID <= 2 AND
Left([Raw_Data], 1) = "@") As Tag
= A02F, 1 + 0

The 0 is because the leftmost character of A02F is not '@'

When tblRawData.RDID = 3 you get:

A12F, (SELECT Count(Raw_Data) FROM tblRawData WHERE RDID <= 3 AND
Left([Raw_Data], 1) = "@") As Tag
= A12F, 1 + 0 + 0

When tblRawData.RDID = 4 you get:

A22F, (SELECT Count(Raw_Data) FROM tblRawData WHERE RDID <= 4 AND
Left([Raw_Data], 1) = "@") As Tag
= A22F, 1 + 0 + 0 + 0

When tblRawData.RDID = 5 you get:

@TPO, (SELECT Count(Raw_Data) FROM tblRawData WHERE RDID <= 5 AND
Left([Raw_Data], 1) = "@") As Tag
= @TPO, 1 + 0 + 0 + 0 + 1

When tblRawData.RDID = 6 you get:

@TPC, (SELECT Count(Raw_Data) FROM tblRawData WHERE RDID <= 6 AND
Left([Raw_Data], 1) = "@") As Tag
= @TPC, 1 + 0 + 0 + 0 + 1 + 1

Note: The query assumes that there are no records with Raw_Data = Null.

James A. Fortune
MPAPoster@FortuneJames.com