[TxMt] match and look ahead?

[Gerd Knops]

Hi,

To make it easier to visually parse blocks, I am trying to write a  
pattern that matches on 'even tabs' and give them a light gray  
background.

I tried something like

     match= "^(?=\\t)\\t";

but that doesn't seem to work. Is look ahead not possible in pattern  
matches?

Gerd