Default settings.
Switch to “VBScript” configuration. (It has “Sub” in its Default Keywords.)
Add “sub_” in Highlight(1). (Color = 1)
Text sample:
sub_
sub_x
_sub_
xsub_
(All the “sub_” are highlighted with color 1.)
Then remove “_” from [Treat the following characters as alphanumeric].
** Now only the one in “xsub_” is highlighted with color 1.
(I have to enable “Regular Expression” option for “sub_” in Highlight(1) to highlight all the “sub_” with color 1. But I don’t think it’s the proper solution.)