The attorney says because of Hopper's grave condition, he can't be questioned by his wife's attorneys in a deposition.
Hopper will appear at ceremony to receive a star on the Hollywood Walk of Fame Friday. His doctor approved the appearance because it is likely to be a positive experience.
Hopper filed a declaration last month saying he was undergoing promising chemotherapy treatments and remained hopeful "that this treatment will be successful so that I may soon resume the full enjoyment of my life and work."
Dennis and Victoria Hopper have agreed to stay 10 feet away from each other while the divorce is ongoing. She has stated in court filings that Hopper filed for divorce to cut her out of her inheritance, a claim the actor has denied.
The case is scheduled for a court hearing on April 5.
The Associated Press contributed to this report.