Joining objects / datablocks in blender and nifskope

[the ghost of persian]

Ok, I am trying to add a scope to a gun. The gun and scope come from different two .nifs and whenever I use the "Join objects" command in blender, they remain seperated after exported in Nifskope. I cannot succesfuly load the mesh into the game like this. How can I get these two objects to combine permenantly?

[Baelkin]

Personally I use Max, but if you have given the scope and the main gun different materials, they will, as far as I know, be exported as separate mesh objects upon exporting from Blender which could be your problem.