Sorry, let me explain a bit better

Let's say there is a chat going on in channel #a:
<jon>hello
<bob>hello
<jon>hows it going?
<bob>good
<jon> nice to hear from you
I want to echo everything jon says to channel #b:
<bot>hello
<bot>hows it going?
<bot> nice to hear from you
Or echo only certain things that Jon says, maybe with additional text in channel #b.
Thanks for the replys