Questions on credit card accounting

[Lee Hauser]

I'm a new Gnucash user. I have the basic checkbook operations down,
but need some advice on some more advanced techniques.

Since we receive rebates on purchases we make with our Costco American
Express card, we use it for a great many things. Considering its high
interest rate, we pay the balance monthly. To ensure we have enough
money to pay the card each month, we treat our AmEx transactions as
debit card transactions...that is, in the paper register, we simply
enter them as if we'd used a check or debit card, but with a special
notation to indicate we used the AmEx. We occasionally transfer these
amounts into our savings account so our checking account is close to
what our checkbook says it is.

Does anyone have ideas how to show this in Gnucash? I'd like to get
the account details in a QFX file from American Express, but that
involves a third account to bring into the mix. I'd like an easy way
to show our AmEx transactions as if they were cash and keep them
separate from real check and debit card transactions, to visually keep
the books straight if possible. Should I try importing the AmEx QIF
file directly into my checking register in Gnucash?

Thanks for any advice.

Lee Hauser