Hi, vedran
This is what I would do if I were you.
1) convert CrossCorrelation from magnitude and phase to a complex number, and then convert the complex number to real and imaginary parts.(Both functions are available in the Numberic->Complex Palettes)
2) Now let's assume the cross Correlation is C+iD, and AutoCorrelation is A, then
A/(C+iD)=A*(C-iD)/(C+iD)*(C-iD)=A*(C-iD)/(C^2+D^2).
Hope this helps.
Ian Ren
Roush Anatrol.