"It was something I always knew was possible. I knew I qualified to play for Scotland but I was not sure if anybody else knew.
"I have been given a bit more of a profile with QPR and I think people are now starting to take notice of me."
The 25-year-old has made an impressive start to the season, banging in eight goals to help steer the Loftus Road side to the top of the Championship.
Mackie cost the South London club £150,000 in the summer and his previous teams include Wimbledon, Milton Keynes Dons, Exeter City, Plymouth Argyle and a loan spell at Sutton United.
Now he faces the prospect of being involved in next month's double-header against Czech Republic and Spain.
And Mackie, who qualifies through his Kilmarnock-born grandfather Graeme, cannot wait to meet up with the rest of Craig Levein's squad.
"This has been a long road for me but I am nowhere near the end of it," added the in-form forward.
"I am not a player who has burst onto the scene as a teen - I've had to work very hard to get where I am.
"I suppose in a way it makes this more satisfying because I've had to work my way up.
"To be honest, the thought of playing against Spain, the world champions, is ridiculous but it makes no difference the opposition, I am just delighted to be involved."
Source: BBC Sport
Source: BBC Sport