Thats ok, i did it with a dax template.

::start/web

<!--[album(all,artist,title)]-->
<!--[volume]-->
<!--[if(cover)]-->RENAME "<!--[cover/]-->.jpg" "<!--[artist/]--> - <!--[title/]-->.jpg"<!--[/if]-->
<!--[/volume]-->
<!--[/album]-->
Just have to replace "<img class=cover width=170 height=170 src="covers/" by "" and ".jpeg">" by "".
Rename the file to .bat, put it in the copy covers directory
and run it.

I haven't find a tag who give only the jpeg file name !

And after copying jpg on albums paths
::start/web

<!--[album(all,artist,title)]-->
<!--[volume]-->
<!--[if(cover)]-->COPY "<!--[artist/]--> - <!--[title/]-->.jpg" "<!--[path/]-->\<!--[artist/]--> - <!--[title/]-->.jpg"<!--[/if]-->
<!--[/volume]-->
<!--[/album]-->