text search and replace

I need a plugin that can search and replace my text on all posts. However, the plugin should only change raw text and not change text inside an anchor,text inside an anchor shoould not be replced plus I want to be able to define the occurence of text replce in a post, e.g max 2 times per post.

There are many search and replace plugin but none of them have the functionalities above. I need a plugin like this because I want to create contextual links within posts.

Please help..thx