raw PROP:*: { echo -a $nick sets the $2 property to: $3- }
This will echo any property change (topic, onjoin, hostkey, ownerkey, language), give the $nick that did it, the property that changed ($2) and what it changed to.
For example...
Dark Sky sets the OWNERKEY property to: newownerpass
If you only wanted password logging, you could use...
raw prop:*ownerkey*:
raw prop:*hostkey*:
You need to be Op in the channel to see prop changes.
Since you're talking about MSN chat, you need to be Owner.