DPlot

If I want to plot Y against X, for eaxmple

s=sin(x)*cos(x*x)*tan(2*x)
y=sin(s*s+s*x+s^2)

I don't want to type sin(x)*cos(x*x)*tan(2*x) for each s in y. How do I do that? So basically, I am asking if Dplot support automatic variable substitution (in this case replace every s in y with sin(x)*cos(x ...