Hello Jill,
I hope the following will help to clear this up a little. When travelling to Zambia you are restricted to bringing in and taking out a maximum 100 Zambian Kwacha. You can however take in foreign currency but it must not exceed US10,000 or equivilent. You can exchange US dollars into the local currency at banks in Zambia and there is a Barclays Bank in the resort.
In terms of Optional excusrions, these need to be paid for in the local currency (Zambian Kwacha).
Hope that helps,
Julia