Change the display style of the text on the STACKLINE.

[hongy...@gmail.com]

I'm using the following code in my forked project [1]:

percol.view.STACKLINE = 'Fold:F1,F2,F3 Push:C-p Pop:M-p Script:M-s Dir:M-d Dircmd:M-b'

I would like to change the display style of the text mentioned above, for example, to underline some characters in it, as shown below:

_D_ir:M-d

How to achieve this purpose? 

[1] https://github.com/hongyi-zhao/ariadne/blob/838179bb4275ac85f5342d9e7d086d6ade3be1de/rc.py#L55

Regards,
HY