Is it possible to add a label to a Funnel Chart that is not linked to a specific data point in the funnel?

I have been asked to scale the funnel so that the height of the neck matches to the KPI of 40%, and they want the funnel labelling at the neck/funnel joint saying 40% .... that is a fixed label pointing to a fixed point of the funnel that is not linked to any added data point.

I would think that this is not possible, but thought I would ask anyways.

Thanks
Steve