use C timestamp with millisecond resolution?

[John Beale]

Kst-Plot is one of the most useful programs I've encountered, and I use it nearly every day. 

I am running kst 2.0.8-3~3319~44~ubuntu18.04.1 on Linux Mint:  4.15.0-58-generic #64-Ubuntu SMP Tue Aug 6 11:12:41 
UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Sometimes I record data from a serial device using "serialplot" by Hasan Yavuz ÖZDERYA which I got from bitbucket.org / 
hyOzd / serialplot

This program has the option to include a timestamp with each line of text recorded in a CSV file.  KST can interpret a C 
timestamp in seconds since the UNIX epoch. However serialplot uses a timestamp with three extra digits for millisecond 
resolution. For example, it saves the first five lines from an experiment running at 7.5 Hz as:

timestamp,Channel 1,Channel 2,Channel 3
1567735105128, -0.000169, -5.2e-05, 0.01
1567735105262, 6e-06, 0.000748, 0.01
1567735105396, -0.001018, 0.000156, 0.01
1567735105530, -8.4e-05, -0.000906, 0.01

The first timestamp indicates Friday, September 6, 2019 1:58:25.128 AM GMT.

Is there an easy way to make use of this kind of millisecond timestamp in KST?  Thanks for any suggestions!

-John Beale