求:简单iis rewrite实现(非常着急中)

rewrite很少涉及现在着急用。。！谢谢各位大侠
如题
http://www.5758120.com/a/kewaiweichuang/dahanxianqingchushu/index.html
如何变为:
http://www.5758120.com/index.php?ac=a/kewaiweichuang/dahanxianqingchushu/index.html
规则是：
请大侠帮帮忙

试试：

RewriteEngine On
RewriteRule ^(.*)$ index.php?ac=$1 [L]