Edmond,

Although it is hacking to the max, maybe this can be of help:

contents of udftest.prg:
LPARAMETERS cDA

IF TYPE('gcDA')='U'
PUBLIC gcDA
gcDA=cDa
ENDIF
IF TYPE('gnGroup')='U'
PUBLIC gnGroup
gnGroup=0
ENDIF

IF TYPE('gnCounter')='U'
PUBLIC gnCounter
gnCounter=0
ENDIF



IF gcDA<>cDa
gcDa=cDa
gnCounter=0
gnGroup=gnGroup+1
ENDIF

gnCounter=gnCounter+1

LOCAL dlcRetVal
dlcRetVal=STR(gnGroup,5)+IIF(cDa='A',STR(gnCounter,5),STR(10000-gnCounter,5))


RETURN dlcRetVal


To use it, try this from the command window:

create table test (cKey C(5), cDA C(1))
insert into test (ckey, cda) values ("10001",'A')
insert into test (ckey, cda) values ("10002",'A')
insert into test (ckey, cda) values ("10003",'A')
insert into test (ckey, cda) values ("10004",'A')
insert into test (ckey, cda) values ("10005",'D')
insert into test (ckey, cda) values ("10006",'D')
insert into test (ckey, cda) values ("10007",'D')
insert into test (ckey, cda) values ("10008",'D')
insert into test (ckey, cda) values ("10009",'D')
insert into test (ckey, cda) values ("10010",'A')
insert into test (ckey, cda) values ("10011",'A')
insert into test (ckey, cda) values ("10012",'A')
insert into test (ckey, cda) values ("10013",'D')
insert into test (ckey, cda) values ("10014",'D')
select udftest(cda),* from test order by 1
RELEASE gcDA,gnGroup,gnCounter

hth,