Assuming that 'manually' means 'manually specified fixed values', here's an example:
insert into DestinationTable (
copy_column_1
, copy_column_2
, manual_column_1
, manual_column_2)
select
copy_column_1
, copy_column_2
, 'manual_value_1'
, 'manual_value_2'
from SourceTable
Edit: fixed syntax error