If I understand what you’re asking, you can use a virtual device which will be defined as both a contact sensor and a switch to smartthings. When you turn on the switch, the sensor will look like it’s open. When you turn off the switch, the sensor will look like it’s closed.
That allows you to have the wise sensor turn on the switch part of the virtual device through Ifttt, which will then make the sensor part looks like it’s open to smartthings.
This is very commonly used for integration with echo routines (not smartthings routines) because of the present time they can only be triggered by a sensor, not a switch. So people turn the switch part on and off with any automation or even by voice and that then makes the sensor part open and close, triggering the echo routines.
It would be a similar idea in your case. And then you could include the virtual sensor in with other sensors or sensor-based automations like smart things Home monitor.
Take a look at the FAQ for the echo routine integration, it includes the code you would need for this type of virtual device. 