TTree alias with parameter?

Dear ROOT experts,

is it possible to create alias wich accept simple numerical parameters?
Let’s suppose I have a TTree many array variables (same fixed length) and I want to draw an expression involving this variables, something like (arr1[i] - arr2[i])/arr1[i].
I know I can use tree->SetAlias with the Form trick, but I want to save the alias in the tree, so that I can use it when I open the tree in an interactive session.
Since aliases use TTreeFormula, I thought of creating a TTreeFormula with parameters, but then I have no idea how to pass the parameters to tree->Draw or tree->Scan.

Is it possible?