This came via The General Specialist:
A free plugin that will let you import, rearrange and use all the available channels in OpenEXR files into After Effects CS3 float project. Brendan Bolles has kindly provided the world with a beta version of a set of four 32 bpc-aware plugins, complete with a sample project and a 49-channel OpenEXR image.
The plug-in is from Fnordware and requires AE CS3