I do this too:
($NUMFOLUP$) <STRONG>$SUBJECT:40$</STRONG>, <EM>$FROMNAME$</EM> <br>
(It helps if you give the version of MHonArc that you are using)
I am guessing you are using v2.0 alpha. In v2.0 there are several
resources that control thread index layout. You will need to set a
few resources to get what you want. The frames demo resource file
is a good example that shows how all the thread resources work.
A trick for debugging is to add unique comment declarations to
resources your are defining. Then you can look at the raw HTML
generated to see where the resources are being used.