MacBook Pro and external microphone

We bought a MacBook Pro 15" Retina a couple of weeks ago. We wanted to use it the same way as our current PC laptop: hook up an external camera via BlackMagic Shuttle Express Thunderbolt (through the Thunderbolt port), hook up an external Sennheiser Freeport wireless microphone (through the 3.5mm combination headphone/microphone jack), and hook up a set of regular headphones (through the USB port).

The idea is to videotape an event, getting good quality audio from the presenter via the wireless microphone (our space has big limitations in terms of using wired devices), and monitoring the audio through the headphones. This is a scenario and a set up where several PC units have worked perfectly well in the past.

However, after spending over $2,000 on the MacBook Pro, we found out that the 3.5mm combination port will not take input from any of the microphones we have. This YouTube video explains exactly our situation: http://www.youtube.com/watch?v=oaiYc9Cqpis (we did not create the video, but the video shows this is a common issue). On the video they explain the plug of a regular microphone has 3 rings or pins, while the plug needed for the 3.5mm combination has four rings or pins.

We spent about 45 minutes with Apple customer support, including a senior advisor, and we were told that as the Apple headphone/mic combination, the one you use with an iPhone (seen on the video above), works in the combination jack, both as a microphone and as a headphone, then there's no issue. Apple does not have any recommendation, solution, or adapter for using a regular 3.5mm microphone with the 3.5mm combination jack, so that an external microphone can be easily used. The senior advisor also suggested a USB microphone instead, but that means a) having a wired microphone, which is not possible in our space, b) buying more equipment, when we already have our equipment, and c) adapting all our setup to the MacBook Pro, instead of the machine being easily integrated into our existing setup (more likely, we will ship the MacBook Pro back instead).

A few discussions on the web (for example, https://ca.answers.yahoo.com/question/index?qid=20110505020946AA8izSV ) mention that this specific laptop expects a "line level" microphone signal, one that would come from a pre-amplifier, so that regular microphones would not be detected. The Apple senior advisor was not familiar with that claim, nor could he shed any light on it.

So our question is: has anyone successfully used an external 3.5mm microphone with the 3.5mm combination port on the MacBook Pro Retina 15"? If so, what kind of microphone did you use? Or, did you have to use any kind of adaptor or amplifier to make it work?

Thank you for any pointers you can give us.