playing audio at a certain point

i'm new to max and need to create a way of a sound file being played from one button but will only play at the first beat of a song (if that makes sense).

I've got a backing track and two different vocal tracks, they are all synced up to work with each other timing wise however i need to have the ability that if the end user presses the "play" button for a particular groove~/buffer~ it won't play until beat one of the bar repetition. Each crotchet is worth 426.5ms so i've set up a metro object to do that which then goes into a counter object that goes 1 to 8, that then goes to a select object so that a bang is outputed when the counter is at 1 but i'm not sure how to patch it all together so a groove object will play at that next beat 1, even if it is pressed at the previous beat 4/5?

any help would be GREATLY appreciated, i'm new to this and my deadline is fast approaching for my coursework!

THANKS!