How to searching text stream columns in SQL

I have a table with a Varchar(max) column that I have created via the HealthShare SQL portal, and I see that in it's underlying class that column corresponds to a  %Stream.GlobalCharacter

When I try to do a text search on that column (referenced as cd.Code in the example below) I get an error

select * 
from DevTools_CodeAnalysis_tables.Code cd
inner join DevTools_CodeAnalysis_tables.MethodData mtd
on charindex( mtd.qualifiedRef,  cd.Code) > 0

It produces the error

 Scalar function CHARINDEX (arg2) not supported for stream fields

How do I search it?