Specifying a clip start time

When you right-click a clip and select Properties, you should get a screen that lets you name a clip, change it's start and end times, etc. You should be able to change the parameter to HMSF for Hours, Minutes, Seconds and whatever F means. Then insert the time you want the clip to start. Are you not getting those options?
 

Well...
I suppose you'll have to set the Now time at the exact spot you want to paste it in for each track.
Now I wonder if your Paste options are the same as mine.
When pasting a clip in, you can set the exact time you want to place the clip regardless of where the Now line is.
Find the audio file you want to insert. Copy it. Go to SONAR and in an empty track, right-click, find Paste (it may be behind Edit) then it should show the time that the Now marker is at and you may be able to change that time to your desired time. Unless that's is measured the same way your Clip Properties are measured.

Theoretically, you can paste exactly where the Now line is. So if you turn off the Snap-to tool, you can place the Now line anywhere. Position it at the exact place your tracks start, then try to paste on the Now line. If you miss, you may have to do a little dragging to get it in the right place.