The rules are generally the same in many countries.
It depends how long you are going to stay in Zimbabwe but if it is less than three to six months you can use, the one from your country as long as your country has the same condition to drive on the left side of the road.
If you are staying for a long time it is advisable to take an international driver's licence. in fact I would advise Expats to take this document from their countries. I would like to believe it is an international standard that you can get an international driver's licence in your country.
In Zimbabwe , a licence will generally cost you $20 and driving lessons ranges from $3 to $5 for 30mins