Warning: Zambia is Wonderful
It'll be an interesting experience, that's for sure!
To convert your license, you would need to sit an Air Law exam, plus a Type Rating AGK and Performance exam for whichever aircraft/aircraft group you will end up flying.
Not being fussy about where you did your training, just that you have the hours and experience, I expect that if you can find an instructor and aircraft in Lusaka, you will be able to carry on your training where you left off. (It wouldn't be so easy to convert a Zambian PPL to an EASA one though).
The aircraft fly the same as they do here, albeit with less gusto when taking off from 4000' AMSL at ISA+20, but the hardest bit will be getting your head around ATC (very TIA/AWA) and their way of saying and doing things, followed by navigating over vast wilderness in 4-8k of visibility.
I know a man or two who may be able to help you out when the time comes. PM me.