mask a layer with multiply transfer mode

Hi,

I've been supplied some illustration in psd format which i need to animate. several of the layers are in multiply mode in photoshop.

I would like to keep them this way if possible as collapsing any layers changes the look + feel of the illustration.

as soon as i mask or track matte any of these mulitply layers in after effects they become "normal" layers so the colour changes and the white background becomes visible.

is there a way of preserving the multiply mode whilst masking?

using afxter effects version 10.0.2.4

many thanks in advance

stephen