i have never heard of a license like that... it would not make sense. africa is a continent with many different countries of which each has their own CAA and set of airlaws etc. some are ICAO and some not.
with that said, i am sure that a JAA ATP would be welcome for validation anywhere. some countries you need to only pay a fee and some you need to write an airlaw exam and do a flight on top of that etc... it depends from country to country.
which country are you planning to go fly in and which register aircraft?
apart from getting a validation, assuming you want to fly that country's register, you also need to get a work permit etc.
i flew south african registered aircraft, with a south african license, around africa on contract and only needed to obtain a work permit and/ or visa for some.