I would like modify HTML like

I am <b>Sadi, novice</b> programmer.

to

I am <b>Sadi, learner</b> programmer.

To do it I will search using a string "novice programmer". How can I do it please? Any idea?

Thank you

Sadi

More clarification:

I get some nice reply with possible solution. But please keep posting if you have any idea in mind.

I would like to more clarify the problem just in case anyone missed it. Main post shows the problem as an example scenario.

1) Now the problem is find and replace some string without considering the tags. The tags may shows up within a single word. String may contain multiple word. Tag only appear in the content string or the document. The search phrase never contain any tags.

We can easily remove all tags and do some text operation. But here the another problem shows up.

2) The tags must be preserve, even after replacing the text. That is what the example shows.

Thank you Again for helping