Copy state/value of one MQTT topic to another?

I’m receiving a state/value on one topic of mqtt and assigned it to an item:

Number V_VAR1 "Pulse Count [%d]" {mqtt"<[mymosquitto:Gateway1-out/16/1/1/0/24:state]"}

However, the device that i’m connecting asks for the state of the topic:

Gateway1-in/16/1/1/0/24

So, i would like the value that is on Gateway1-out/16/1/1/0/24 to be pushed automatically to Gateway1-in/16/1/1/0/24, is this possible to do on the item file or do you advise me making a rule to accomplish this? I just automatically thought i could add something like , >[mymosquitto:Gateway1-in/16/1/1/0/24:<state or command>:<trigger>:<transformation>] to the item.