sed替换问题

[ransomhui]

cat dialpeer.cfg

[ws-skype-f]
#TREEITEM = wholesale
priority = 900
hunt_mode = 0
gateway = skype-f
override_proxy_mode = 2
capacity = 5
dst_pattern = 0030..........

[ws-skype-a]
#TREEITEM = wholesale
priority = 903
hunt_mode = 1
gateway = skype-a
override_proxy_mode = 2
capacity = 3
dst_pattern = 0030..........


[ws-skype-b]
#TREEITEM = wholesale
priority = 903
hunt_mode = 1
gateway = skype-b
override_proxy_mode = 2
capacity = 4
dst_pattern = 0030..........

[ws-skype-d]
#TREEITEM = wholesale
priority = 903
hunt_mode = 1
gateway = skype-d
override_proxy_mode = 2
capacity = 3
dst_pattern = 0030..........


我要用sed将第四部分
[ws-skype-d]
#TREEITEM = wholesale
priority = 903
hunt_mode = 1
gateway = skype-d
override_proxy_mode = 2
capacity = 3
dst_pattern = 0030..........
中的capacity = 3 改为 capacity = 0


查了一下sed只能做目标字符的前后一行，像这个目标字符后的第二行如何处理呢？