How to use Gpio_SetConfigString for VF modules

I have VF61 module. I need to change the pin level of one of the pin. I am using Gpio_SetConfigString as
success = Gpio_SetConfigString(hGpio, io1, NULL, lvl=1, StoreVolatile); but it gives error as lvl=1 undeclared identifier. How to use this function to change pin level.

@Abhinav: Parameters you have given to API are in incorrect format:

BOOL Gpio_SetConfigString(HANDLE hGpio, uIo io, const TCHAR *reserved, const TCHAR *value, ParamStorageType storageType);

If you check the above API declaration, 4th parameter should be in pointer to TCHAR (string), you have use it in " " for value lvl=1, than it should be working.
For example:

success = Gpio_SetConfigString(hGpio, io1, NULL," lvl=1", StoreVolatile);