A GUI label from a config file

[Anish Mangal]

I wonder if it is currently possible to have the label of a GUI element
come from a variable in a config file.

For example, A QT GUI Range block's label is
str('Power: ' + ch_1_label)

Where ch_1_label is coming from a variable config block. However, when I
run the flowgraph I get the error
'UnboundLocalError: Local variable referenced before assignment' error

Thoughts

-- 
Anish