Plot horizontal line (e.g. limit line) in ViVa

Hi,

I want to add a horizontal line to the ViVa plot (e.g. for a transient plot).

I do not want to use the "h" button in ViVa.

I want to define the y-value of the line via output expressions as a function of a design variable.

How can I do that ?

BR

Holger