You can't really embed it, but you can overlay it. You tag the SVG with a 
"relative" position and then move the modbvalue with an "absolute" position over 
it:

<svg style="position:relative" width="400" height="100">
  <rect width="300" height="100" style="fill:rgb(255,0,0);stroke-width:3;stroke:rgb(0,0,0)" />
  <div class="modbvalue" style="position:absolute;top:50px;left:50px" data-odb-path="/Runinfo/Run number"></div>
</svg>