Gary Bain has been ordered to appear personally at Jedburgh Sheriff Court.
His case is part of the unruly behaviour that has resulted in police patrolling Hawick High School, the court heard.
The 37-year-old of Burnfoot Road, pleaded guilty to a charge of threatening or abusive behaviour by making a threat of violence at the Morrisons supermarket car park in Hawick on September 28.
The court heard that Bain approached a group of youths at around 8pm looking for a 16-year-old boy involved in a dispute with his daughter over a mobile phone earlier on.
Procurator fiscal Graham Fraser said: “When the youths said he was not there, he made various threats, saying he was hunting for him and he’d better watch his back and that his days were numbered.
“The friends were concerned at the threats.”
Mr Fraser said that a member of the Bain family had posted a photo of the 16-year-old on Facebook accompanied by threats.
He added that the accused might have been misinformed about the background to the dispute.
Mr Fraser said: “Hawick High School is currently been in the news for unruly behaviour, and this is part of some disgraceful behaviour which has been going on.
“The fact that an adult is condoning and pursuing these matters is of great concern.”
Defence lawyer Ed Hulme claimed Bain’s 13-year-old daughter had been assaulted by the 16-year-old boy, causing her dad to lose his temper.
Sheriff Peter Paterson said he was concerned that the accused was judging the facts of the case and seeking retribution “based on a potential misunderstanding”.
He deferred sentence on Bain until January 8 for a personal appearance.