As long as the fitting is solidly screwed to the cam cover wall, it shouldn't matter too much if it protrudes inside the passage or not (it may suck a bit more oil if it doesn't protrude, that's all).
patricks said:
... it is only 2mm in diameter ... Will this do??
Any extra crankcase ventilation should help in your case, but honestly I can't tell for sure in advance if an extra 2mm Ø fitting will be enough to make a solid difference.
With a recently cleaned up OEM 2.5mm Ø metered orifice (4.9mm2 cross sectional area), plus the extra 2mm Ø fitting (3.14mm2) you'd be at 8.04mm2 total.
Thing is, I don't really know the status of the metered orifice in my engine (haven't taken out my inlet manifold to check yet). It may be clean like yours (4.9mm2), or it may be completely clogged up (0.0mm2). So with my extra 3.5mm Ø fitting (9.62mm2) my current total area is anything between 9.62 and 14.52mm2.
I believe your engine has higher mileage than mine (200K km). If I had to guess, I suspect an extra 2mm Ø fitting might not be enough to make a difference in your case.
The only real way to discover is empirical test, that's why I used an elbow to which I could screw different fittings of varying internal diameters until I found the diameter that worked best (3.5mm in my case):

Best place to get gadgetry of this kind is some pneumatic components store. Just an example in Oz: http://www.pneumaticsolutions.com.au/