Book Keeping And Payroll Management

We are looking for an experienced person to control our weekly, monthly book keeping duties and payroll for our company. The job should only require say 15-20hours per week, but we seem to have a lot going on so we need experience in accounting, payroll, and general financial management. 
We run Xero for main accounting system and also work along side an external Accountant for overall accounts management. 
This would be an ideal job for someone who's been working full time inside a business and looking to ease back to a part time role. Experience in accounting is essential. We do have a few complex things to tend to.