"We have already mailed it. We expect it [to be heard] in early February," Andriy Domansky said on Sunday.
The attorney added he was going to file a complaint against two searches in his own house, which he called a "vendetta."
"I will challenge what they [Prosecutor General's Office] did. I will take action within the law. I can defend my rights… in European courts, if need be," Domansky said.
Vyshinsky was detained in Kiev last May on charges of high treason and supporting the bid for independence by two breakaway regions, which carry a maximum penalty of 15 years in jail. A court in the southern city of Kherson has upheld his detention until February 16.
Russian President Vladimir Putin has called the case politically motivated. Harlem Desir, representative on media freedom at the Organization for Security and Co-operation in Europe, has called for Vyshinsky's release.