Hi Nick,
If you are recording 4 tracks into Samplitude at 24/96, you will want to setup the recording in a virtual project.
If you want to write out certain audio segments, first, you click on the lower 1/2 of the object to select the object. The you mark the range you want to export with the mouse. Select the range by clicking the mouse on the upper 1/2 of the object and dragging it.
If you want to ensure that you are grabbing on object boundaries, set "snap to grid" on. (this is the little magnet icon. Snap is also a handy tool for aligning objects to a cursor position.
Once the range is selected, go to File->Export Audio->Wav and it will give you a save dialog.
Select the name of the track, and be sure to check the radio button here which says "export marked range". There is also a button there to specify the file format, mono, stereo, bit-depth, etc. but in this case you will likely want to maintain the same format. The default will be to the option "Create one file".
This is how you would create one file from a selected range. To ensure that all files are time-aligned, put the cursor at the start of the object. Then select the ranges of objects on other tracks by dragging from the right top of the object and dragging it left until it snaps to the cursor position. (I hope the way I am describing this is making sense.) The starting point of each exported file will then be sample aligned, because each marked range has been snapped to the cursor position.
This works for any number of tracks.
Another way to do it is with the "Convert Audio" -> "Save in Format" dialog. I'm sure that there are one or two other ways also. Samplitude has lots of options.