It appears that certification as a translator into one or more languages is not generally given by a university or school's language department, or even by a government agency, but by a professional association of translators and interpreters, of which often a school's or university's languages' or translations' center or department(s) is/are also a member.  

All the major languages in the world, (with the glaring exception of Arabic), and some more local languages, like Czech, Hungarian, Hebrew, had such an association as of 1979, the publication date of a reference book compiled and edited by Stefan Congrat-Butlar, published by R.R. Bowker Company, and titled: "Translation and Translators: An International Directory and Guide".  I recommend aspiring and established translators and interpreters get that book, say, via www.amazon.com, or www.powells.com, or directly from the original publisher at 1180 Avenue of the Americas, New York, N.Y. 10036.  I am not aware of a more recent edition.    

Of the 33 nations that are listed in that edition, and which have one or more national associations of translators and/or interpreters, 31 have one or more of their associations as members of the UNESCO-sponsored FIT (Federation Internationale des Traducteurs; International Federation of Translators), based in Paris.      I would recommend contacting the FIT to see if your nation has a members-controlled association of translators affiliated with the FIT.     

If there be no such association in your nation or language group, you might ask the FIT for guidelines and materials on how to go about organizing one.  Don't forget to contact the schools and universities in your nation or language to encourage them to be institutional members of your proposed national association, and to work with informed people on developing tests for certification in any desired language paired with your own.     

As for developing testing materials and procedures for certification of translators and interpreters within any pair of languages in which one is your native language, you could get help from the ATA (American Translators' Association).  They have an excellent web-site, with a button entitled "Certification".  I believe one can also be an individual member, or an agency member, of the ATA without being a citizen or resident of the USA.    

If you wish to consult the 1979 Directory, you might find a copy at an area public or university or even private library or net-work of libraries organized as an inter-library-loan association.