//echo # $pos(meis is test,$+(is,$chr(32)),1)
echoes 3 because of meis, please test code before posting it, especially when it is this easy to test.

If you just want to split the text into the part before and after 'is' use this code:
alias new {
  var %pos = $findtok($$1-,is,1,32)
  var %is-item = $gettok($1-,1- $+ $calc(%pos - 1),32)
  var %is-value = $gettok($1-,$calc(%pos + 1) $+ -,32)
  echo -s %is-item == %is-value

If you really want the position of the 'i' character from 'is' try this:
$calc($len($gettok($1-,1- $+ $calc($findtok($1-,is,1,32) - 1),32)) + 1)

That will return the number of characters(including the space in front of 'is') before the word 'is'.

$input(Me like stars, You too?)