libdigiapix i2c write

Hi Im trying to use the libdigiapix I2C API to write to a register in a slave device.

Looking at the documentation here: I can see that there is an i2c_write function and an i2c_transfer function.

The write function lets you specify the slave address but not a register address on the slave device youre writing to, while the transfer function lets you specify a register value on the slave to read from/write to, but I cant see how you can pass a value to write to said register with this function.

For example, I have a slave device at address 0x68, with an 8 bit register at address 0x14 that I need to write an 8 bit value to to set/clear certain bits. Is it possible to even do this with either of these library functions?