It's not so straightforward to do this sort of thing by clicking buttons via the user interface, but if you know how to code in MATLAB there are some functions in SPM that could help. Essentially, you could do something similar to the following...
P=spm_select(2,nifti,'Select DTI and AAL'); V=spm_vol(P); V(2).mat = M*V(2).mat; % where M is the appropriate matrix. spm_reslice(V,struct('mask',false,'mean',false,'interp',0,'which',1,'wrap',[0 0 0],'prefix','r'));