Add amount at checkout

Hi
Wonder if anyone can help

When a customer rings us to place an order, we just go through the store as the customer would.
However sometimes I need to add an amount on (example AM delivery would cost an extra few pounds)

Instead of adding lots of shipping options it would be great if I could just add £2 etc onto the amount

Is there anyway that I could adjust the coupon code so that if I put a +200 it would add the amount ON not take it off

example the amount is £20 coupon code is 200 = £18 total - but if I did +200 ="22

would it be easy to put a variable into the coupon code which would only add on if the + symbol was used

Thanks
Ron

You have some strange math.. 20 - 200 = 18... I assume you mean 2.00

But how do you know if its AM delivery? You should just add "AM delivery" as a shipping option. How will you know when to charge extra?

Hi
No you misunderstand
AM delivery was just a generic example,

OK
say for example im doing an order, and Im at checkout and the customer wants something else that isn't in the shop and I say yes, we can do that, but it will cost £2 extra.

is there a way of simply adding £2 to the total (without having to program it into admin 1st)