get/set.Setting to pvr.iptvsimple

Hi all ,

I am struggling with a Python script were I want to get/set Addon settings (to another Addon, in this case 'pvr.iptvsimple').
This used to be no problem, but ever since the 'pvr.iptvsimple' supports multiple instances (instance-settings-1.xml, instance-settings-2.xml, etc) I can't seem to find how to get/write these Addon-settings properly...

(Simplyfied) Python code:

import xbmc,xbmcaddon,xbmcgui,xbmcplugin,xbmcvfs

PVR_ADDON_ID = 'pvr.iptvsimple'
PVR_ADDON = xbmcaddon.Addon(PVR_ADDON_ID)

pvr_dns = PVR_ADDON.getSetting('m3uUrl')
pvr_write_dns = PVR_ADDON.setSetting('m3uUrl')

I've tried modifying the lines (to add instance-settings-1) but no success:

pvr_write_dns = PVR_ADDON.setSetting(instance-settings-1, 'm3uUrl')

I can write strings directly to the xml file (with success but 'scrambles' other settings in .xml file right now), but would like to ingegrate this properly/better.

So the question is (for example 'm3uUrl'): How do I get/set setting 'm3uUrl' from/to 'instance-setting-1' in 'pvr.iptvsimple'?
Anyone?