Is it possible to have character data in crosstab (not sum, count)

Hi,

I am trying to do a cross-tab report with character data inside

i am tryning with layout editor but impossible

now i'm trying with rtf template

there's no problem with count(USER)  but when i want the name like max(USER) it's impossible

my crosstab is :

lines = days

column= name of a car

and in cell it's the name of user who rent this car during the day

i'm looking for on the web but i don't find examples

in oracle reports it's very easy and i do that in 10mn

but for this report with BI  i've already used two days