ADC channels and port pins

Question

I am developing a device converting adc input into data and transmitting them and receiving them at other place,I cant figure out between analog input eg:AIN0 and the port pins please help
I have included the code here using NRF24LE1 Keil 
 relation between AIN0 and POO and how to connect 
 void adc_init(void)
{
hal_adc_set_input_channel(HAL_ADC_INP_AIN0);
hal_adc_set_reference(HAL_ADC_REF_INT);
hal_adc_set_input_mode(HAL_ADC_SINGLE);
hal_adc_set_conversion_mode(HAL_ADC_SINGLE_STEP);
hal_adc_set_power_down_delay(HAL_ADC_PDD_0US);
hal_adc_set_acq_window(HAL_ADC_AQW_075US);
hal_adc_set_resolution(HAL_ADC_RES_8BIT);
hal_adc_set_data_just(HAL_ADC_JUST_RIGHT);
} 
 port pins 
 
 P0DIR =0x03;

P0=0;
 
 P0CON = 0x70;
P0CON = 0x71;