Bibliography alphabetical sorting - how to override system language settings?


I am a Czech, using Endnote X4 for writing a thesis in English, the language of all the citations is also English.

I’ve encountered the following problem while creating bibliography (alpabetical sort orded):

Even if I set in Tools/ Sort Library that the library should be sorted by the English language (alphabet), the bibliography is sorted according the Czech alphabet rules ( when for example CH is considered a special character and sorted different from C). The language of the document is set for English too.

Could anyone help me?