voxelwise analysis for secondary dataset

We would like to run conn analyses on both volumes and surfaces for the same dataset.  Is it possible to include the volumes as a secondary dataset, but still have the volumes go through denoising and have them included in the voxel wise analysis (for each source, have a map for the primary and a map for the secondary dataset)?  Or am I better off just doing two projects, one for the volumes and one for surfaces?

Thank you!