sql server - Select a table by value inside BLOB column -

we use ado , sql server.

our table has blob column xmlfield, inside blob store complete xml file information.

      <xml>           .... much text , fields ....      <\xml> 

reading , writing xml field no problem

how can build query select datasets xmlfield contains text / word

select * mytable xmlfield contains special word    

or

select * mytable xmlfield contains special field  , has special value