Can we merge as a single column

Question

select
    case 
        when 'A-3258' like 'A-3258' 
            then '3258' 
            else 'Unwanted' 
    end as R1,
    trim(leading '-' from (trim(leading 'B' from ('B-3258')))) as R2 
from 
    dual;

Can we make results in single column.

R1    R2
==    ==
3258  3258

Expecting

R1
==
3258
3258