Lowry was brought on in the 15th minute of the tie as a replacement for the injured Ianis Hagi and produced a man of the match display which saw him open the scoring for the Scottish champions.
Van Bronckhorst heaped praise on the Scotland under-19 international and indicated he can become a permanent fixture in his first team squad.
“If I put him in, it’s because I have trust in him and his abilities,” said van Bronckhorst. “When he is performing like this, he makes his manager and everyone at the club proud.
“Of course, it wasn’t planned for Hagi to have to come off so early in the game but we could bring Alex on and you could see he was really enjoying his football.
“I’m really impressed with him, the times he has trained with us and tonight you saw what he can bring to the squad.”
“I have been at Rangers since I was 10 and scoring out there was just a dream,” he said. “I never expected the opportunity tonight. But as soon as Ianis went down, I thought I might get something. When I got called over I was just buzzing.
“There were a bit of nerves coming on but when I started to relax I thought I did not too bad - a couple of sloppy moments but I can work on them on the training ground.
“The Lowland League has been good, challenging playing against tough teams week in and week out but it has set me up to play on nights like this.
“The manager has been amazing to be fair. All the staff have been brilliant. I am just thankful to them for giving me my debut. I’ll not be swapping my shirt!”