I understand the struggle you're having, and all I can say is that I'm glad I'm on this side of the table rather than the other.
It really does depend on how you are viewing this code. Is this a workplace code intended to create a healthy work environment? If it is that, then the gamut and the tools of discipline should be fairly limited.
If this is really, truly, a code of conduct for members, period, that covers a whole range of harassment, from verbal harassment, discriminatory harassment, sexual harassment, and so on, and the concern is that ultimate forms of this really do undermine the member's capacity as a member of Parliament, and ultimately the House should be able to discipline members, then it is a different kettle of fish. You need some way to transition from the normal human resources, healthy environment, anti-harassment process through to a House of Commons disciplinary process.
That is where I have trouble, and I know you do too. If third parties are involved in the human resources dimension of it—let me call it that—how can they be put in the position of, say, we think this is serious enough that the House should consider it as a disciplinary matter?
Partly it depends on who you have involved. If it's someone like the Conflict of Interest and Ethics Commissioner, who is usually a former judge, that person has reputation and status, and one might say the informal authority to take an informed opinion as to whether this is really serious. That person may be better suited to do that than, say, the human resources officer in the House of Commons, who could do well with a mediation issue.
You may want to have a hybrid system whereby if something is deemed really serious, it's passed up to another level of consideration and investigation and information gathering. You might have an initial process that determines some of the facts. If it can be dealt with through conciliation and mediation, terrific. If it really exposes some pattern of egregious behaviour or even a single egregious behaviour, then it might be passed up to someone with a higher level of authority and prestige who could then make the recommendation back to the House that this be investigated.