Ooops, yes, that was totally under my nose :)
Thank you very much.

Jean-Christophe 

> On Jun 30, 2017, at 18:18, numbchild@gmail.com wrote:
> 
> Check out the docstring of variable `org-capture-templates`.
> There is a doc like this:
> ```
> %\1 ... %\N Insert the text entered at the nth %^{prompt}, where N
>               is a number, starting from 1.