Slider: Custom value for "ON" using switchSupport

In the Android App I use Sliders with switchSupport for my dimmers. When I tap the item in the app, it toggles the state of the dimmer from 0 to 100 or from [1-100] to 0. Great feature.
But I need a different value for ON (not 100). Is that possible and if so how?

What does the app actually send as a command? Look in your events.log

Where ON and numeric commands are both available, you may use a proxy Item on your sitemap, and rule to do what you wish with commands, before passing to the “real” Item. Another rule or cross-linking can update the proxy from the real Item state, depending on bindings.