Sorting with non-english characters

[Mkranj]

Referencing this issue for the R implementation: smartinsightsfromdata/rpivotTable#123
Rows aren't sorted correctly when Croatian letters are included:

Example:

engleski, francuski, hrvatski, talijanski, češki, španjolski

Expected order:

češki, engleski, francuski, hrvatski, španjolski, talijanski

Is there some way to define character order to use when sorting?
Could this be defined in a new locale file for the Croatian language? If so, I'd be up for making the translations for the Croatian locale, including the localeStrings, aggregator names etc.