Voice alerts on designated points in channel

I’m trying to set few voice alerts on one channel. For example ch5 flightmode. At -85, -53, -20, 12 points. Is there way to do it? I assume I should use some remaining unused channels or virtual channels to „clone” throttle value and than play alert for each channel? I really don’t have enough experience to do it for now. Can anyone help me with that and point how to do it properly?

Ok it's good to discuss with ourselves and find some answers in many tries.
For now I got:

[virtchan2]
template=complex
[mixer]
src=Ch5
dest=Virt2
[mixer]
src=AIL
dest=Virt2
scalar=-85
usetrim=0
muxtype=voice
curvetype=fixed

[virtchan3]
template=complex
[mixer]
src=Ch5
dest=Virt3
[mixer]
src=AIL
dest=Virt3
scalar=-53
usetrim=0
muxtype=voice
curvetype=fixed

Virt2=286
Virt3=287

So basicaly it works, but plays each step when I cross desired range. I expected to play voice only in desired points.But if I go from -85 to -20 directly by switch it plays voice for middle value -53 which I don't want, only that -85 and -20. Is there a way to separate that? Or I have to assign some switch position as play condition if that is possible? So for example If I move from -85 to -20 i'll do it by switch FMOD0.
It's little too complicated how exactly that mixer works

Yes, I think you'd have to use a switch to ensure only one alert would play. Not sure if it might work to use one virtual channel as a switch for the other.