I am not sure what is your question.
-you can generate the code for a TCutG (like any other ROOT object) with:
mycut->SaveAs("mycut.C");
in your case take the code from mycut.C, removing the Draw statement.
-to use the cutg with your tree t1, do
mycut->SetVarX("zco1");
mycut->SetVarY("tof1");
t1->Draw("tof1:zc01","mycut");
Rene