how to dispoly in a text (on a graphic) underlined character with a subscript?

I got the answer to underline a character in a text on a graphic : ('\underline{X}', 'Interpreter', 'latex') BUT

1) I cannot display Xbar (X with a dash on it)

2) It seems also impossible to add a subscript as the following command does not work: ('\underline{X}_{1}', 'Interpreter', 'latex')

Do you have solutions for these questions? Thanks

[Walter Roberson]

I would try

'\underline{X_{1}}'

Answer 1

[Image Analyst]

'\underline{X_{1}}' doesn't work either. You'd think

title('\underline{X}_1', 'Interpreter', 'latex');

should work because it should underline the X and then the underline says the 1 after it should be a subscript, just like

title('X_1', 'Interpreter', 'latex'); % 1 is a subscript.

does. But it does not. I tried a few things and couldn't solve it either. MATLAB does admit they don't support the full latex instruction set.