If you want the pushrod at the center of the tailplane you'll probably have to use a control-line style elevator horn that has a metal control arm welded or braised to a piano wire U-shaped joiner. These are available from several sources including SIG, Brodak, etc. They generally are for smaller (.35 to .40) size airplanes and they aren't used much in RC, with the exception of some RC Scale use where the pushrod must be hidden.

What are you building?