[INTERFACES] Ip exclusively through a certain interface

Hey guys,
i’m rather new using Mikrotik devices and i’m having a hard time with an WLAN/Interface (Needn’t to explain what’s this WLAN is)
Basically, all i want to do is, xxx.xxx.xxx.xxx IP goes EXCLUSIVELY through interface 2 (for example).

For instance, there is a public IP that, whenever requisited by my network, it must go through the interface i want, if the interface isn’t
connected/disabled then, the requisitions made by my network, to that IP specific and only, mustn’t work…

Is there an way?

I need this to aply my failover rule.

(Sorry if wans’t clear enough, language barrier.)