Need to convert ASCII Dec serial data stored as a string to ASCII characters stored as a string and push to network connection SSID & network password

[gusgonnet]

@luculent

set these variables, from the device itself, when the SSID info data is already on the device itself”.

oh, I misunderstood.
Once the library gets the new credentials from the app, it will set them like @ScruffR mentioned.
Then if you wanted to reset the device (one way to force the device to connect to the new Wi-Fi) you can do this in the callback function like so:

@gusgonnet

// callback for when the wifi credentials are set by the app or library
void provisionCallback()
{
    // avoid a timeout error on the app side
    // this gives time to the app to disconnect on its own
    delay(1000);

    System.reset();
}

Note: the delay(1000) is optional.