How to fill dots between equation and tag(equation numbers) in align environment?

Question

Actually I searched this forum already and found some helpful answers under this link: How to get dots in between equation and equation numbers with equation is centrally aligned?

I applied these tricks in an equation environment

\def\equation{\old@equation\small\hskip\textwidth minus 0.87\textwidth}
\def\endequation{\hbox{ }\leaders\hbox{$\cdot\,$}\hskip \textwidth minus
 \textwidth\old@endequation}

It works fine in this new equation environment. However, when I tried to use these tricks in an align environment, it does not work. I also tried to rewrite the \maketag@@@ macro as following:

\def\maketag@@@#1{\hskip -\textwidth \leaders\hbox{ }\hskip 0.5\textwidth \hbox{} \leaders\hbox{$\cdot\,$}\hskip\alignsep@\hbox{\m@th\normalfont#1}}

It works some how not so perfectly, because some '...' overlaps with the equation:

And after defining the \maketag@@@ macro, the equation environment is also destroyed.

What I really want is the equation looks like this picture:

I know there is a trick to realize this function in align environment like this:

\begin{align}
  e^x&=1+x\multido{\i=2+1}{6}{+\es{\i}}\notag\\
  \hskip 0.1\textwidth
     &\multido{\i=8+1}{6}{+\es{\i}}+\cdots\leaders\hbox{$\cdot$\,}\hskip
     0.18\textwidth\hskip
     -0.18\textwidth\label{eq:etoXseries}     
\end{align}

But I think it is not user friendly, because I must add additional codes in each line. I want to realize this function in the align environment, which means one can use like this:

\begin{align}
  e^x&=1+x\multido{\i=2+1}{6}{+\es{\i}}\notag\\
       &\multido{\i=8+1}{6}{+\es{\i}}+\cdots
     \label{eq:etoXseries}     
\end{align}

and the align environment will fill $\cdot$ between the equation and number automatically.

I hope that I have explained my questions clear enough for you all.

Waiting for your answers. Thanks a lot!