Add zeros to cell to make same length

Hi

I have a range of columns with various text and value data that I need to concantenate. Each column needs to be a specific length e.g.

Name Reference ouput required
James A1234 00James0A1234
Tom B102 0000Tom00B102

i.e. Name needs to be 7 chars and reference 6 chars.

Is there a formula that can do this?

Thanks for your help.
James

Ron, thanks that is perfect.