text -> char

I want to extract portions of a TEXT column into a CHAR(8) column:

> create table one (descr text);
> create view  two as select substr(descr, 2, 4) as d from one;
> \d two
View    = two
Query   = SELECT "substr"("one"."descr", '2'::"int4", '4'::"int4") AS
"d" FROM "one";
+-----------------------+------------------------------+-------+
|      Field            |          Type                | Length|
+-----------------------+------------------------------+-------+
| d                     | text                         |   var |
+-----------------------+------------------------------+-------+

> create view three as select CAST(substr(descr, 2, 4) as char(8)) as
d from one;
> \d three
View    = three
Query   = SELECT "substr"("one"."descr", '2'::"int4", '4'::"int4") AS
"d" FROM "one";
+-----------------------+------------------------------+-------+
|      Field            |          Type                | Length|
+-----------------------+------------------------------+-------+
| d                     | text                         |   var |
+-----------------------+------------------------------+-------+

SELECT INTO behaves the same way. It seems impossible to cast a TEXT into
a CHAR.

The char() function works neither:

> create view four as select char(substr(descr, 2, 4)) as d from one;
ERROR:  parser: parse error at or near "substr"

Any ideas?
This is 6.5.2 (RH Linux 6.1)

Thanks in advance

peter