Scripting buttons with OPC tags

Hi guys, I’m still getting the hang of ignition so please bare with. so far im really enjoying this platform and its UI.

Just want to get some ideas/ advice on how you would tackle this layout…
I have 2 analogues for (e.g.) a motor speed, one for an automatic and a manual setting.
My idea is to allow the user to dial in a speed, choose either auto or manual and then apply the settings with another “GO” button.

I’m not so sure on the best way to tackle this in Vision designer…I’m thinking of using if statements…assign manual and auto to a tag value and if that tag value is a certain state, the “GO” would then send the digits to the plc?
even then…which script function would be best to execute this?

Thank you all in advance for the help & the patience