Range Operator for first 2 letters of item

Hello all,

Quick question about range operators in PowerShell. The following code uses a range operator to return all items under C:\ that start with A, B, or C:

Get-ChildItem 'C:\[a-c]*'

Is it possible to have a range operator that would get me items that started with 2 or more letters, e.g. items that start with 'Ab' - 'Ag', or items that start with 'Co' - 'Cz'?