Insert Pool Name into serverside HTTP Header

Is your requirement to send the traffic to a pool when it matches the path

(or)

Send the traffic to a pool when it matches the path along with the header being inserted.

I understand the part that you dont want to put multiple if else condition, this could be simplified with an Irule & datagroup combination or by other filters like extracting details from the path & framing the pool variable name automatically. Its just the requirement needs to be more specific. Can you please clarify this.