You can try using Dual() for the dot expression, the first parameter for the value to show, the second to position the dot like:
Dual(Num(%Expression,'0%'), BarExpression*1.2)
The *1.2 may not be accurate, more complex expression will be needed to keep the same distance, maybe using a variable to calculate the value of the larger bar and from there a fixed numeric distance to use in all bars
