Does the iPhone dock allow the headset to work through it’s line-out port?

[benvallack]

I'm wondering if the Line out port on the iPhone dock support the microphone input signal from the iphone headset. I'm basically wondering if I could use an adaptor on the dock so use a third party microphone with the iphone, without using the audio port on the iphone itself? Perhaps someone with a dock could try their headset in the dock line-out port and see if it uses the headset’s mic? Many thanks.