The group was set up 2015 and is made up of business leaders from both the public and private sector who want to raise the value of diversity and inclusiveness throughout the business community.
McLean said the New Zealand arm of the bank had been collecting diversity data for the past eight to 10 years and reporting back to its Australian parent company.
He said collecting the data across 44 different business in New Zealand would help establish a base case here.
McLean said it treated the diversity issue as any other business problem.
"You measure it - and set yourself targets."
McLean said he was reluctant to go down the route of using quotas.
"Compulsion is a very heavy-handed instrument. I would like to get there through market forces."
So far using market forces has resulted in glacial change when it comes to getting women on boards in New Zealand.
A recent census of women on NZX-listed boards by AUT found the percentage only increased from 14.75 per cent to 22.17 per cent between 2012 and 2017.
But McLean pointed to targets working for the bank and said it had set a target of getting to 50 per cent women in senior leadership roles by 2016 and it did get there.
He said one of the challenges for the bank was areas that were seen as male-dominated like technology and finance.
If there was a team which had all men, the bank required a short-list with at least two women on it when it came to new job applications.
He said unconscious bias was an issue that was hard to combat at the micro level and "therefore you need to use a blunt instrument".
An example was when a male leader departed who had done a very good job and people were looking to replace them.
"You have a picture of a person and think we need someone like Jim or Peter."
But McLean said there was growing awareness of the diversity issue and the debate was shifting away from what are the benefits to how do we achieve it.
He said if organisations were going to be male-dominated they would increasingly stand out and have to justify why they were like that.
Asked when New Zealand would reach gender equity McLean said he believed a tipping point would come.
"I think there is a tipping point that will come. Where it becomes very hard not to do it."
The first report on the data is expected to come out mid way through next year.