Identify a French movie about an alien temple in Indochina containing a liquid that mutates people

Question

I am trying to identify a movie I saw as a child in the late 1980's.

• The movie is in French, and takes place in the modern world (1970's or 1980's)
• The bad guy was a French helicopter pilot during the wars in the French Indochina, where he was shot down and his copilot was killed.
• He was shot down near an ancient temple that houses alien technology.
• In the modern day, the good guys travel to the temple and find the helicopter's wreckage with the remains of the copilot
• In the temple, there is a long hallway with a high ceiling and tall statues on both sides. The statues shoot laser beams from their eyes down on anyone trying to pass them in the hallway
• The good guys use a heavy metal door from the temple and carry it above their heads as a shield from the lasers. By the end of the hallway, the door is cut in half.
• The temple stores a large metal jar of some alien liquid.
• The bad guy captures the jar, and while using a laser to cut it in a laboratory, gets some of the liquid inside sprayed on himself.
• This liquid instantly mutates the bad guy into a monster with multiple eyes or one extra large eye in the middle of his forehead.

Answer 1

This is Curse of Snakes Valley (AKA Klątwa Doliny Węży) from 1988.

There's quite a nice synopsis here

Professor Tarnas is working on university in Paris and specializes in ancient cultures. One day he is approached by older man Traven, who was a veteran of Indochina wars. That man showed Tarnas a piece of writing in ancient language that only few people in the world can understand. Traven told professor the story of what happened to him during the war, when he was pilot of helicopter shot down somewhere over the jungle. Wounded Traven roamed the area and accidentally found the ancient temple and inside a strange artifact. Traven stole the artifact for which he was cursed by the monks from the temple. Now he needs the help of professor Tarnas to find the temple again. While they are talking someone puts poisonous snakes into the room, but some workman is attacked and killed. Young journalist Christine tries to gather informations about the snakes attack, but instead stumbles upon Tarnas and much bigger story.

For the record, the film was made in Polish, so it's likely that you were watching a dubbed version.