How to add leading zeros from a number format to create a text number format

[jldrd0718]

I have 1 column (Georeference) and virtual column of (Pole number). I want to set virtual column (Pole number) to a 7 digit text number whereas leading zeros will be expected.

Sample
Georeference: 123456
Polenumber: 0123456

How to set a formula in the virtual column in order a 7 digit with leading zeros will be reflected?

Thanks