Ok I wrote some code to illistrate what i want, the true code has less lines in the mainwindow than listbox lines (multiple listbox lines map to one line in the mainwindow, how i do this isnt really important for what i need tho)
The mainwindow has some lines that are wrapped and some that are not, any line might be or might not be. In my example I have simply randomized them.
They are liekly to be mostly one way or the other, but could potentially be mixed.


Code:
alias ex1 {
  window -c @ex1
  window -el20 @ex1
  var %i = 1
  while (%i <= 100) {
    var %line, %j = 100
    while (%j) { var %line = $+(%line,$chr(3),$calc(%j % 16) %i) | dec %j }
    aline $iif($r(0,1),-p) @ex1 Line %i ----- %line
    iline -l @ex1 1 Line %i
    inc %i
  }
}
menu @ex1 {
  lbclick : { 
    ///echo -st LBCLICK $active : $1- : $line($active,$1,1)
    sline -l $active $1
    ;^ activate the select the listbox line
    ;
    var %num = $gettok($line($active,$1,1),2,32)
    ;^ get the correct mainwindow linenumber (true code this is more complexe but results the same with %num being the line)
    ;
    var %rev = $chr(22)
    while ($fline($active,$+(%rev,*),1,0)) { rline $active $v1 $mid($line($active,$v1,0),2) }
    ;^ this removes any and all highlighted (reversed) lines in the mainwindow
    ;
    rline $active %num $+(%rev,$line($active,%num,0))
    ;^ highlight (reverse) the selected line in the mainwindow
    ;
    sline $active $line($active,0,0)
    ;^ This line is a patch to make the following line work correctly each time
    ;
    sline $active $calc(%num + 1)
    ;^ This line selects the line following the highlighted line, thus makes the highlighted line appear near the bottom of the mainwindow
    ;
  }
}


OK what im after is to get the mainwindow highlighted line vertically centered in the window, rather than near the bottom like the code does currently
I would like it to work fullscreen and windowed, i not concerned if it goes crappy if someone makes the window so small the line cant be shown, thats just being annoying

Any help anyone?

PS: If all the lines are not wrapped the code was pretty simple...
//sline $active $calc(%num + ($window($active).dh / ($height([],$window($active).font,$window($active).fontsize) + 1) / 2 ))