Hi Quim,
if you need it urgently, check out
http://expressjs.com/api.html#app.listen
and also mojito/lib/index.js
Mojito: 1. creates an express app with createServer(), 2. adds a store to the app and 3. adds middleware to the app.
It should be straightforward to change step 1. according to the
app = https.createServer(express)
pattern... Let us know how it goes.
Ron