You can use the INSERT... EXEC... construct to save the results of stored proc BB into a temp table, then read from that. You'll need the @name parameter to pass into BB though, your sample code didn't show where that came from.
Something like:
create proc BB
@name varchar(50)
as
select cep from table where name = @name
go
create proc AA
as
begin
create table #result (cep int)
insert into #result exec BB @name
select top 1 @cep = cep from #result
if @cep > 1000
select table1000
else
select table1001
drop table #result
end
go
https://technet.microsoft.com/en-us/library/aa175921(v=sql.80).aspx