How can I extract a lessequal char from SQL_Latin1_General_CP1_CI_AS?
varchar doesn't support ≥: unicode only

This includes the literal '≥' which is varchar too

Collation here doesn't matter: this is sorting and comparison only never seen this before!

Some more SQL to use your table

SELECT ASCII('≥'), CHAR(61), '≥'
GO
insert into char_test values ('≥');
GO
select item, ASCII(item) from  char_test;
GO
select replace(item, '≥', '&gt;='), replace(item, '=', '&gt;=') from  char_test;
GO


create table nchar_test(
    item varchar(10) collate SQL_Latin1_General_CP1_CI_AS,
    Nitem nvarchar(10) collate SQL_Latin1_General_CP1_CI_AS
)
go
insert into nchar_test values ('≥', N'≥');
GO
select item, ASCII(item), Nitem, UNICODE(Nitem) from nchar_test;
GO


Edit: after more playing

If you have a value then use CP 437

select CAST(Nitem COLLATE SQL_Latin1_General_CP437_CI_AS AS varchar) from nchar_test;
GO
select CAST(N'≥' COLLATE SQL_Latin1_General_CP437_CI_AS AS varchar)
GO


Note: the ASCII is 242 but this won't give either :-)

SELECT
   ASCII(CAST(N'≥' COLLATE SQL_Latin1_General_CP437_CI_AS AS varchar)),
   CHAR(242),
   CHAR(242) COLLATE SQL_Latin1_General_CP437_CI_AS


You may be able to control this with database collation but frankly use unicode...