CASE(?) to write in a different column based on a string pattern

Hi,
     I need to create a CASE (I think) statement to check for a string 
pattern, and based on its value, write a substring in a different column 
(alias).
I'm trying to create a COPY statement to port a table into antoher 
database, which has a table with another format (that's why the aliases)

Let's write it in pseudoSQL:

given this

select pattern from tbl;
pattern
----------
foo1234
bar5678
baz9012

That's what I'm trying to achieve

select
     pattern,
         CASE when pattern like 'foo%' then ltrim(pattern, 'bar') as foo
                   when pattern like 'bar%' then ltrim(pattern, 'bar') 
as bar
                   when pattern like 'baz%' then ltrim(pattern, 'baz') 
as baz
         END
from tbl;

|foo   |bar  |baz |
  1234
             5678
                         9012
(hoping text formatting is ok... 1234 should go in column foo, 568 in 
bar and 9012 in baz)

Is it possible?

Thanks in advance
Moreno.-