Hi Matthew,
You could trying using ""+{END}"" with a Global Send keys (non events). This would only work in the event that the cursor is at the start of the text. You would have to write some send keys functions to establish where your cursor is however the above should work, if not, try the ""+{HOME}"" which will select it the text in the other direction.
Remember to activate fields with a Global Mouse Click Centre before using send keys other wise you get unexpected results.
Let me know how you get on.
Thanks,
James