Slicing One video into 5 individual measured sections

I would make a grid graphic (easily done in Photoshop) and use the crop effect (program monitor) on each of the images.

Masking an image with a shape does not allow you to set an in and out point. (need to nest and slide the image.)

Make the first slice:

• Add the video to a sequence with the same frame size.
• Go to Sequence > Sequence Settings.
• In the Frame Size Width (W), add " / 5" to divide the width by 5.
• Copy the new width or write it down.
• In the Timeline, click the FX badge on the video clip to open the Effect Controls.
• Set both the Position and Anchor Point X values to 0. This will move the far left side of the clip to the edge of the frame.
  
  

Make the second slice:

• Duplicate the sequence and load it in the Timeline.
• Go to Effects and find the Transform effect, drop it onto the clip.
• Click the FX badge on the video clip to open the Effect Controls panel.
• Under the Transform effect, set the Anchor Point X value to the width of the sequence and the Position X value to 0.
  
  

Make the third slice:

• Duplicate the sequence and load it in the Timeline.
• Click the FX badge on the video clip to open the Effect Controls panel.
• Select the Transform effect, then press Cmd/Ctrl + C to copy and Cmd/Ctrl + V to paste.
  
  

Repeat these steps two more times to make the fourth and fifth slice.

Do you want five vertical bars from left to right?

You can try doing it with Masks, but I am not sure how precise you could get it.

You could create a Graphic for each bar with a Shape enabled as a mask for a video layer.

You could also do it in After Effects - either via an After Effects Composition in your Premiere Pro Timeline or by rendering the Comp and importing the resulting clip.  On the After Effects side, Solid Layers could be set as Track Mattes for each vertical bar.

It would probably  be easier to find a hardware solution. I'd ask B&H or Adorama.