Select
   c_busname,
   c_last || ‘, ‘ || c_first
from
   cust
where 
   c_customer = customer_id

define   alfa     char(100),
         a_bustname   like cust.c_bustname,
         a_last           like cust.c_last,
         a_first          like cust.c_first,
         alfa_concat    char(???)   # ??? you must see if you can put in a fixed 
                                            #dimention

# i presume that custumer_id is another number variable, if not then you must quote like "\"" before and after... 

let alfa = "select c_busname, c_last, c_first from cust 
    where c_customer = ", customer_id

prepare alfa_exec from alfa

declare alfa_cursor cursor for alfa_exec

foreach alfa_cursor into a_bustname, a_last, a_first

   let alfa_concat = a_last, a_first

   {
    now you have in alfa_cancat the concatenation of the two data from
    the a_last and a_first, where you can use for what you want to do with
    it...
   } 

end foreach