zoom while video recording

[i hear black]

I tried shadow rom 0.0.1 a while back and noticed the camcorder has a zoom
feature. sapphire runs the best on my phone, but it doesn't have the zoom feature
on the camcorder. I pulled the camera.apk out of shodowrom but was not able to get
it to work in sapphire (system/apps rename camera.apk to camera.apk.bak, reboot,
copy the shadowrom camera.apk to system/apps, reboot.) after that when I click on
the camera icon it says there is no app installed. is it possible to install the camera.apk from a
different rom into sapphire? if so, could someone please point me in the right direction?
thanks.