Inbound Call Routing Condition

I have 4 PSTN trunks and for PSTN trunk number 4, who is called PSTN4, i want to filter inbound numbers starting with 702 to extension number 5238. I know this is done with a condition but i dont know exactly how.

I know for the caller ID it is “CALLER==702XXXXXXX” but not for the PSTN trunk. I tried:


but when saving it says it is not a valid rule… How can i do this??

If any other info is required please let me know.