Well, let us make sure the SPI port expander channel setup by MikroC is functioning correctly. Do you have a voltmeter? If so, send an interlaced byte "10101010" down to the LCD and holding LCD pins in that pattern and then measure the data pins with respect to GND.That's very kind of you!
Hopefully if the C18 code is simple enough for me to understand I can send the commands the mirkroC way!
This will ensure you have successfully piped the byte to the LCD. You can also then send "01010101" to verify the control of the SPI port expander channel.