I'm trying to make a table where the row lines only span a percentage of each column (say 75% centered on the middle of the cell). In other words instead of connecting column lines like this "H" they look more like |-|. Additionally I only want some of the columns to have this and not all of them (for example columns 1 to 3 of a 4 column table. I could do this if I used FIXED width tables using \rule but it requires a width parameter and I haven't been able to figure out how to make the width adjust to whatever the width of the column ends up being.
Possible avenues might be to use \rule in a way I haven't tried. Or to modify \cline so it doesn't span the whole column.