Parameter As Column Name?

 Greetings,
 
    I am developing a search form that uses a DDL to select a column name and a text box to define a search term.  Code follows:
 
     1 cmdSearch = New SqlCommand( "select * from sites where @columnName like @sTerm order by site_name", conSites)
2
3 cmdSearch.Parameters.Add( "@columnName", SqlDbType.Text).Value=ColumnParam
4 cmdSearch.Parameters.Add( "@sTerm", SqlDbType.Text).Value=searchParam

  
The problem I'm running into is that the @variable appears to imply single quotes about the value.  This is fine for @sTerm, I just removed the quotes from the concatenation and it reads the value correctly, but it appears to break @columnName and the query returns no values.
 
If I manually substitute an appropriate column for @columnName sans single quotes, it works.
 
How can I eliminate the implied single quotes from @columnName so that the query will read it properly?