Huh? Your question makes no sense.
A sandbox is a test area, somewhere people can test and investigate things without breaking anything. It has nothing to do with MOSS and nothing to do with moving stuff out of MS Access, and there is no way that your 'large sharepoint lists' are using MS Access.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability