NifSkope can now export models to .Nif(but its the wrong version,newer than BC), supposidly there is a converter to convert new .Nifs to the old ones Bridge Commander uses, but people dont seem to be able to post a link where we can get this converter or put it up as a download because there is also a .Nif plug-in for Max 7,8,9 but it wont export the right .Nif version for BC,hence the converter..
Anyway,back on topic, Keep up the good work,will always love your modeling skillz