The "beta" package is available and can be downloaded here (v0.5, update of May,28th,2013), please read the README-IMPORTANT file which is located in the package. You need to select "Finnish" as input language in MacOffice 2011 to activate the Latin spellchecking.
Be aware that this package was designed on MacOSX 10.6. On MacOSX 10.8, 10.9 and 10.10, the Apps sandboxing feature can prevent the options dialog box from saving the spelling options. This problem is fixed in the MacOffice2016 version.
The MacOffice2016 package is now available and can be downloaded here.