Artktecture and Christophe,
I believe the issue is that artktecture is in Canada, and likely using the USA library. W Sliding3 in the USA library does not have the option to choose the number of sliding sashes.
The International library (which you are using Christophe) is much more flexible.
I have found a similar situation with sliding doors. The International library has many configurations but the USA library in some cases doesn't have a suitable object. I ended up getting someone to "convert" a few sliding doors from the International library to work with the macros in the USA library.
Artktecture, I'd recommend downloading the International version of ARCHICAD and looking at the objects there.
Eli Chiasson
Dexel Architecture
http://www.dexel.ca
AC19-23 USA+MEP • i7-7700 3.6GHz | 32GB RAM • Windows 10 Professional