What datatype shud b taken in FDT ,if i want a N8 in my ddm

hEY GUYS,

i HAVE TO USE A n8 FIELD IN MY PROGRAM…
wHAT SHOULD IT BE DEFINED IN THE FDT…AS THERE IS NO OPTION OF n FORMAT WHILE WE MAKE A FDT…AVAILABLE OPTION IS PACKED…AND NOT NUMERIC…

format U = unpacked numeric

hey thanks…i kw it was a very silly…question,…
Actually i m a beginner…Thanks…