[NTG-context] \hl line thickness

Hello, there is a way to select the line thickness of a \hl[n] command? I want to use \hl[n] for a fillin space in a question/answer document. The \fillinline, \fillinrules, ... are not good for my goal because they extend the horizontal line until the end of the line. I need several fillin space of different width on the same line for question like: Complete the following sentence: bla bla bla __________ bla bla bla __________ bla bla bla______. The \hl[n] is ok for this but I like to have a thinner line. -- Andrea De Michele