PROGMEM equivalent
In that case you have 3 options I think:
1. Use a microcontroller with an EEPROM (L0, L1 series) and place the user settings there
2. Use one of the available EEPROM emulation libraries - http://www.st.com/en/embedded-software/stsw-stm32066.html
3. Use your own functions to read/write data into the Flash memory, but be aware of flash wear-leveling problem if you want to save the settings frequently