What an amazing story! Other than at the above link, where is this story recorded? Your link provides no source.
64. The Victorious AdmiralLooks like the location changed in the telling, but it's obviously the same story.The very reverend Father Provincial Kuck, of the Franciscan province of Bavaria,heard, himself, the following incident related by Admiral Don Mondemar,during his visit to Spain, when convoked to the General Chapter, held at Murcia. The then reigning King of Spain, Philip IV, determined to send a fleet to recapture Oran from the Moors. Several attempts had already been made, all of which had failed, and the fortress was considered impregnable. In spite of everything the admiral could say, the king persisted in his determination, and,consequently, nothing remained but to obey. On reaching Alicant, Don Mondemar allowed his troops to disembark, and availed himself of this opportunity to visit the church of the Franciscans, dedicated to St. Anthony,where he placed the whole business in his hands. With this intention, after spending some time in prayer, he called upon the superior, begging of him to have the office of St. Anthony said. This being ended, he, in the presence of a great many people, asked the Father Superior's permission to have a ladder placed before the high altar, over which a life-size statue of the saint stood. This granted, he mounted the ladder and clothed the statue with all the insignia of a Spanish admiral in active service, and thus addressed the saint: "You, St. Anthony, must capture Oran, for I am unable to do so;" and laying his hand on the head of the statue, continued: "You are now the admiral, and I am only your humble servant and soldier, ready to obey your orders, for after God,I place my whole trust in you." This ceremony concluded, he came down from the ladder and returned with his men to the fleet, where they embarked. As the squadron drew near Oran, all waited anxiously for the enemy to begin the attack. Seeing no notice was taken of them, the admiral ordered his men to fire. Again no response from the citadel. At a loss to understand what this meant, the command was given to land the troops, and, to the great astonishment of every one, the city gates were wide open. Thinking this was a stratagem of the enemy, they proceeded very cautiously through the empty streets, which, like the fortress, were completely deserted. Here an old Moor was discovered, concealed in his house, and was immediately brought before the admiral, who demanded an explanation of this extraordinary behavior on the part of the garrison and inhabitants. "As soon," replied the old man, "as the Christian squadron appeared in sight, a legion of soldiers was seen in the air, led by a Franciscan monk, wearing all the insignia of an admiral on duty, who threatened to destroy every one of us if we did not at once leave the city. Terrified beyond description at this unexpected apparition, both citizens and garrison had fled in the greatest disorder.It was in this way that, thanks to the assistance of St. Anthony, Mondemar captured the city of Oran, without shedding a drop of blood. He at once sent a dispatch to the king, informing him of all that had taken place. The statue,clothed with an admiral's insignia, is still to be seen at Alicant, but the miracle was only confirmed in Rome in 1770.
“...Your link provides no source.”
A brief search and I could find no additional sources or citations, unfortunately.
However, such miraculous incidences with great saints have not been uncommon and many citations of such can readily be uncovered, so let your faith grow through the account regardless.
There are a variety books on Saint Anthony’s life that would be well worth the read. His popularity is very high on the historical list.