For that you can do below:
"IF IT HAS ONE LINE THEN:
READ CUSTCODE INDEX 1.
IF SY-SUBRC IS INITIAL.
WRITE:/ 'Customer Code :', CUSTCODE-LOW.
ENDIF.
"If multiple lines
Loop at CUSTCODE.
WRITE:/ 'Customer Code :', CUSTCODE-LOW.
ENDLOOP..
Thanks,
Naveen