Not through regular font formatting. You can accomplish it using the Advance
field, but it's a bit tedious to get right because proportional spacing
makes the "l" value hard to predict. For example, I was able apply a red
line through the word "easily" by placing the following field code right
before the word "easily":
{ ADVANCE _____ \d4 \l30 }
By itself, that just puts a line through. However, if I format the ______ as
red, then the line through "easily" is red. (You could likely do it using
the EQ field, as well)
It's tedious enough, however, that I wouldn't use it very often.