How to show curve current value in note?

I have a curve plotted in HyperGraph. I can add a noted to the graph that is attached to curve and shows the static value (Y axis value) of the curve at the location when the note is attached.

I want to however show within the note the 'current' value of the curve when animating. That is, for the note attachments point to follow the current time value during animation?

 I'm sure this must be relatively easy to do but can't find the correct Templex command(s)?

Thanks.