Concatenation of a field order by a value in a different field

[#1]

Hello,

I've the following table:

FIELD A (NOKEY)	FIELD B (NONOTA)	FIELD C ( RIGA)
LI11703020120117000000001	XXX	10
LI11703020120117000000001	YYY	20
LI11703020120314000000010	AAA	10
LI11703020120314000000010	BBB	20
LI11703020120314000000010	CCC	30

The concatenation of the FIELD B should follow the order of the FIELD C for the distinct value of the FIELD A

How do I give this indication to the function used? The function used is the following:

aggr (Concat (DISTINCT NONOTA, ''), NOKEY)

But I get a concatenation unordered for the field B and it's wrong.

I would like to have the following string in output AAABBBCCC  while I get the following string AAACCCBBB.

Thanks.

[#2]

hello, the problem is that I have to use the sorting of the field C for concatenating strings in the B field relative to the distinct value of the field A.
Failing to use the sort of field notes I C are concatenated according to the value of the first letter in the cell.