Obtaining Burkina visa (Ouagadougou)

A Malagasy friend of mine would like to travel to Burkina Faso this coming July for a visit but there is no Burkina embassy in his country (Madagascar). I would appreciate any suggestions on how he might obtain a visa. I know in some countries it is possible to arrange a transit visa by email that he shows to customs agents upon arrival at the airport, and then he applies for a tourist visa once he is in country. I appreciate any suggestions on how to facilitate this.