PIC18 control registers
The ADCON0 register varies between Microchip processors.  And Microchip definitions vary for different versions of their SDK / libraries.  

Assuming "CHS&lt;4:0> Analog Channel Select bits" applies to your chip, all this means is that 5 contiguous bits of this register are set aside to pick an analog input source.  They could be the 1st through 5th bit.  They could also be the 4th through 8th bit.

The notation "ADCON0.CHS4" suggests you are only assigning a value to the CHS4 bit in the ADCON0 register.  In order to select an analog input you need to assign a value to all the CHannelSelection bits.  Assuming the CHS bits start in the 3rd bit position and all other bits are zero or will be change as needed to 1 later in your code:

   ADCON0 = (0x14 &lt;&lt; 2);  // Select ADC Channel


Or we can extend your original code:

  ADCON0.CHS0 = 0;  // 0
  ADCON0.CHS1 = 0;  // 0
  ADCON0.CHS2 = 1;  // 1
  ADCON0.CHS3 = 0;  // 0
  ADCON0.CHS4 = 1;  // 1