A spokesman said the post had been created due to the surge of interest it was seeing in the region from retailers seeking to become Costcutter members.
Powley was previously business development executive for the south west. He joined after a stint with hosiery manufacturer Pretty Legs.
Before that he spent 11 years as wholesale foods sales director at Booker. He will report directly to sales director David Thompson.
Costcutter has also promoted Darren Shuttleworth from store manager to area manager for Cornwall, Devon and Somerset.
And Mark Dew has become area manager for Hampshire, Berkshire, Dorset, Wiltshire and Bristol. He worked in store management for several years for Lidl.
Costcutter last month said it aimed to expand its core store portfolio and forge more deals with independents.