using html.erb as a stand alone file


I know this isn't good practice and certainly not what rails is all
about but is this possible. I need to customize my CRM to use stripe
which it doesn't support at present.the CRM is written in Ruby and has a
number of rhtml pages. Can I add my own display page of html.erb
extension to these pages to receive a variable on one of the CRM's
existing pages written as: <%= (basket.to_f_withvat).to_money %> On
this stand alone page I can then assign this variable: 'basket_total =
(basket.to_f_withvat).to_money' and then use this to pay with the Stripe
Gateway as below

  charge = Stripe::Charge.create(
    :amount => basket_total, # This is your value as a variable.
    :currency => "usd",
    :card => token,
    :description => ""

---- etc
Again I know this isn't what RoR and MVC is all about, but it's the only
way I can think of doing this.