Townsend will be the third number 10, behind Gordon Ross and Brendan Laney, that Ian McGeechan has used in three games as the Scottish coach searches desperately for his first win this season.
Townsend said: "I'm really happy to be in the team and I'm not concerned about being moved around as long as I'm in the 15.
"I had ambitions to be playing at 10 and it was frustrating sitting on the bench against Ireland.
"At that point I didn't think I would be back in the team at number 10 two games later, especially when they used another centre the week after against France.
"Stand-off is my favourite position and of the 11 years that I've played club rugby, only three of them have been played elsewhere.
"But the coach obviously went with the team that he thought would win the first two games and I wasn't part of that.
"And it's only natural that if you lose two games then there are going to be some changes.
"Fortunately for me I'm back in but if me and the other guys who have come in don't take our chances, then there's some good players who will step in to replace us.
"You have to play well to keep your position and that's what I have to do now if I want to play in the rest of the games."