Function That Replaces Ntext And Compares Ntext With Nvarchar

I am running this query to an sql server 2000 database from my asp
code:
"select * from MyTable where
MySqlServerRemoveStressFunction(MyNtextColumn) = '" &
MyAdoRemoveStressFunction(MyString) & "'"

The problem is that the replace function doesn't work with the ntext
datatype (so as to replace the stresses with an empty string). I had
to implement the MySqlServerRemoveStressFunction, i.e. a function that
takes a column name as a parameter and returns the text contained in
this column having replaced some letters of the text (the letters with
stress). Unfortunately, I could not do that because user-defined
functions cannot return a value of ntext.

So I have the following idea:
"select * from MyTable where
CheckIfTheyAreEqualIngoringTheStesses(MyNtextColum n, '" & MyString &
"')"

How can I implement the CheckIfTheyAreEqualIngoringTheStesses
function? (I don't know how to combine these functions to do what I
want: TEXTPTR, UPDATETEXT, WRITETEXT, READTEXT)