Ian, I had meant to include this screenshot before showing how to do this, sorry for the delay; If you want AUC_t1 to t2 you can add an ODE to the model and capture the value at t2 in a table statement; e.g
#deriv(AUCt1_t2 = (t>t1)*(t<t2)C)
deriv(AUCt12 = (t>0)(t<12)C)
deriv(AUCt12_24 = (t>12)(t<24)C)
deriv(AUCt24 = (t>0)(t<24)C)
deriv(AUCt999= (t>0)(t<999)*C)
deriv(AUCtinf=C)
Simon 
)*c)>
