Insert Expresssions in Task Description in 4.7 / 6.20

[Griffiths, Mark]

All,
 
I think I must be missing something obvious here:
 
I am creating a workflow in 4.7, WAS 6.20 and I am maintaining the long Task Description.  The old menu path 'Insert>Expression' has disappeared and there is no obvious replacement.
 
Has anyone else found this? Obviously I can just type in the text into the old command editor, but there must be a way to select from the container?
 
Any tips would be much appreciated.
 
Cheers,
 
Mark