Dynamic order direction

I writing a SP that accepts as parameters column to sort and direction.

I don't want to use dynamic SQL.

The problem is with setting the direction parameter.

This is the partial code:

SET @OrderByColumn = 'AddedDate'
SET @OrderDirection = 1;

…

ORDER BY 
    CASE WHEN @OrderByColumn = 'AddedDate' THEN CONVERT(varchar(50), AddedDate)
        WHEN @OrderByColumn = 'Visible' THEN CONVERT(varchar(2), Visible)
        WHEN @OrderByColumn = 'AddedBy' THEN AddedBy
        WHEN @OrderByColumn = 'Title' THEN Title    
    END