The Spanish team of Tommy Robredo and Maria Jose Martinez Sanchez will go into the final as favorites but Murray and Robson have formed a strong partnership and won all their mixed doubles matches in the competition.
Former Wimbledon junior champion Robson, 15, has lost all three of her singles matches this week but believes she can beat Martinez Sanchez, who is ranked 26th in the world, in the final.
"I played her in a practice set before the tournament started, and I won," she said after helping Murray to beat Russia 2-1 on Friday.
"I know it's only practice but I am telling myself practice is basically a match, so technically I am 1-0 up."
Murray, who has been unbeaten all week, has faith in his young team mate.
"Laura's definitely got a chance in the singles and we'll have to wait and see what happens," Murray said. "I want to win the tournament now."
Robredo has also won three consecutive singles matches and has triumphed twice in four encounters with Murray so the Scot knows he could face a close match on Saturday.
"It's important to stay patient and it's going to be a tough match because he's played great this week, but if I play well I've got a good chance of winning," Murray said.
(Editing by Clare Fallon)