如何使用其值生成多个节点权重，然后使用sql server 2008计算父子层次结构中所有子节点的总和

I have a scenario, where i have to find percentage of each child node by multiplying node value with node weight, (e.g NodeVal * (NodeWeight/100)), then sum these computed values of all child nodes and add it to its parent, now at one level up this newly computed parent also has its weight, which will be multiplied with its value and then we will compute sum of all child nodes at this level and add it to its parent one level above, and so on.I have a scenario, where i have to find percent