[Exim] MYSQL STATEMENT FOR USERID

Hi Friends,

I am trying to get USERID from mysql database.

When i set user = 5000, The mail gets delivered to particular box. ( AS
Shown in configuration below)

 virtual_local_delivery:
    driver=appendfile
    file= 
/mail/${substr_0_1:$local_part}/${substr_1_1:$local_part}/${substr_2_1:$local_part}/${local_p 
art}
    delivery_date_add
    envelope_to_add
    return_path_add
    user = 5000
    group = exim
    mode=0600

But when i set user = "select id from EMAILADDS where
domain='${domain}' and alias='${local_part}'"
It give the error
LOG: 0 PANIC DIE
Exim configuration error
"user" option set for the second time in line 213

Can anybody help me in this matter.

Rgds
Jai