progressive number

[#1]

I need to count in progressive thdocuments:
example:

customer invoice no.
AAA 105 1
AAA 106 2

BBB 305 1
BBB 605 2
BBB 702 3

CCC ..........

the No must be grupped by Customer and by document
is it possible to do in script?
may be in For loop or for each loop?
Thanks
Regards
Slash

[#2]

hi ,

use something like this

load

Customer,

Invoice,

if(previous(Customer) <> Customer, 1, peek(Counter) + 1) as Counter

resident

Tab1

Order By

Customer,invoice

;