Hi,
As far as I can see from reading the datasheet everything is controled by the ADCON0 register. Here's my untested shot at it:

Code:
Result var BYTE

TRIS = %00000001		'Set GP0 Input, rest as outputs.

ADCON0.7 = 0     		'Set GP1 as digital
ADCON0.6 = 1	 	'Set GP0 as analog
ADCON0.0 = 1	 	'Turn ADC module ON

ADConvert:
    ADCON0.3 = 0
    ADCON0.2 = 0	            'Select AN0 for covertsion.
    ADCON0.1 = 1	            'Start conversion.

    While ADCON0.1 = 1       'ADCON0.1 will be reset when conversion is done
    WEND                          'so lets wait here 'till then.

    Result = ADRES	'Store result.

Toggle GPIO.1		'Or whatever.....
Pause 250
Goto ADConvert		'Do it again.
May work, may not, have a look at section 7.0 in the datasheet.

/Henrik Olsson.