Why lanes? Whats wrong with tracks? However if you are looking for a way to use the lanes for comping try moving the tracks to one track. Place one on top of another. Then show lanes.
Also
Importing material from another SONAR project
You use the Edit > Copy and Edit > Paste commands to import material from one project to another
using the Clipboard. The project that contains the material you want to import is the source project.
The project into which the material is imported is the target project.
Normally, if you copy material from several different tracks to the Clipboard, the information will be
pasted back into separate tracks. You can choose to paste all the material from the Clipboard into a
single destination track in the target project.
You can also copy material from one project to another by displaying the Track view for both projects
side by side, then using drag-and-drop editing.
From the X3 Sonar manual page 321