Is there a legal way to obtain a search warrant for an attorney's office?

I don't know of any way for a search warrant to be obtained by someone outside law enforcement, because ordinarily it's only law enforcement officers that can execute the warrant (conduct the search).  If the prosecutor decided that the hidden evidence was relevant to a pending investigation (not a closed case), the prosecutor or the police would prepare an affidavit stating their probable cause to justify the search, and ask a judge to sign the warrant.