OK, done that; just so we're on the same page, here the full script I'm running
inside the dbus bash session:

#!/bin/sh

email=emiliano.heyns@han.nl
username="staff\\hnse"
echo $password

gconftool --type string --set /apps/activesyncd/accounts/$email/serverUri
'https://weboffice.han.nl/Microsoft-Server-ActiveSync'
gconftool --type string --set /apps/activesyncd/accounts/$email/username
"$username"
gconftool-2 --set --type=string /apps/activesyncd/accounts/$email/password
$password
#SYNCEVOLUTION_DEBUG=1 syncevolution --print-databases loglevel=4
username=$email backend=eas-events

EAS_DEBUG_FILE=activesyncd.log EAS_DEBUG=5 /usr/libexec/activesyncd &
syncevolution --daemon=no --print-databases username=$email backend=eas-events

(password is supplied by the environment). This generates the attached logfile,
and ends in the following error:

[ERROR] fetching folder list: GDBus.Error:org.meego.activesyncd.Error.Failed:
HTTP request failed: 401 - Unauthorized