Peter,
A language has not much to do with a culture.
Most part of languages are done by the OS and Net versions. By telling that
the culture is Belgian and the language is Dutch, the computer with a French
OS does not change by that its user interface.
Your own part of text in your program should be done using the RESX files.
You can try to use the properties of the form of that, however don't think
it is an easy way, at least you should then very well familiar with all the
natural languages that you use.
Cor