Concatenate

Hi I want to concatenate

data : v_date like sy-datum,

v_time like sy-uziet,

v_sess_name type D0100_MAPN.

Concatenate 'RB40' v_date4(4) v_time0(4)into v_sess_name.

CONCATENATE '0' V_SESS_NAME_NEW SY-MANDT

'ADMIN ' ' ' ' ' '/'

INTO WA_BGR00.

I want 7 spaces after ADMIN,

8 spaces for date

1 space for Keep as is in BGR00 table...

but when I concatenate my output is for e.g.

0RB4010130845200ADMIN/

IT IS NOT CONSIDERING THE SPACES IN BETWEEN. How do I get the spaces in the final output ??