Vertical line pointing to fixed Date

Dears,

In majority of my pivot charts, I need to draw a vertical line to point to specific Date
like below example



Normally, I draw it using Insert/ Shapes
but it has one drawback, each time to Update my chart with new Daily data,
it moves and I've to drag it back to the specific Date point

Is there any solution to force the Vertica line to be always pointing to specific date
and never move regardless of the new daily data I will keep updating !