Depends upon which country your ATPL is issued from. I believe if issued from an ICAO compliant state it should not pose a problem.
Typically the CAAP will validate your ATPL, then after flying 200 hours in a RP registered airplane it can be converted to a CAAP ATPL.
Be prepared to take an Air Law exam, English Language Proficiency test and have a Medical exam, as well as obtaining a NTC Radio License.