Server making assetBundles

I am developing an application and i intend to give users the posibility of uploading their own 3D objects. My plan is to let the server place the uploaded objects in a assetbundle and set it aside for the user to download. I have read about assetbundle servers but never with a users input. Does anyone have experience with this or has an idea how to tackle this problem.

Thanks for your help!

Found the answer using the AssetImporter as i intended in the first place. For some reason I tought I had to instantiate the object in order to bundle it. That was a false assumption and by just adding the project path you can assign a bundlename to a asset.

foreach (string file in filesInFolder)
{
    if (!file.Contains(".meta"))
    {
        AssetImporter importer = AssetImporter.GetAtPath("Assets/models/" + file);
        if (importer != null)
        {
            importer.assetBundleName = BundleName;
            Debug.Log("assetBundlesAssigned");

        }
        else
        {
            Debug.Log("No asset selected");
            complete = false;
        }
    }
}

When all the assets are assigned you can build them as usual like so.

public static void ExecBuildAssetBundles()
  {
      Debug.Log("Building bundle");
      BuildPipeline.BuildAssetBundles("Assets/AssetBundles", BuildAssetBundleOptions.None, 
  BuildTarget.Android);
  }