The best way is to take a transfer Bus from the Tur Bus company (www.turbus.cl) from the airport to the Bus station in Santiago (Tur Bus has his own bus terminal. It´s called: Terminal Alameda). The price is aprox. 1500 CLP (Chilean pesos)
Then you take a new Tur bus from Terminal Alameda to Talca. The price is aprox. 3500 to 5000 CLP (Chilean pesos) depending on the comfort of the buses. https://www.turbus.cl/wtbus/indexCompra.jsf.
Special prices in Ecohotel for the conference attendants (Special rate for UCM). You will Have to mention that you 'are attendants to Ms. Cecilia María Fuster Bonvallet firstname.lastname@example.org or email@example.com)
Eco Hotel. The prices are:
Single room is 95 USD/day
Double room is 105 USD/day