Sqlite using dbCommand returning "unknown error insufficient parameters supplied to the command"

Question

This works in SqliteStudio with values for parameters, but it does not work with dbCommand and parameters. "pages" is a sqlite FTS table.

INSERT INTO pages (
    docnumsort,
    pagenumsort,
    content
)
SELECT
    @docnumsort,
    @pagenumsort,
    @content
WHERE NOT EXISTS(
    SELECT
        @docnumsort, 
        @pagenumsort,
        @content
    FROM
        pages
    WHERE
        docnumsort = @docnumsort 
        and pagenumsort = @pagenumsort
)

objCommand = Sourcedb.GetCommand("INSERT INTO pages (docnumsort, pagenumsort, content) SELECT @docnumsort, @pagenumsort, @content WHERE NOT EXISTS(SELECT @docnumsort, @pagenumsort, @content FROM pages WHERE docnumsort = @docnumsort and pagenumsort = @pagenumsort)")

objCommand.Parameters.AddWithValue("@docnumsort", lDNS)
objCommand.Parameters.AddWithValue("@pagenumsort", lPNS)
objCommand.Parameters.AddWithValue("@Content", txtToIndex)

objCommand.ExecutNonQuery

Tried everything I can think of.