Thanks... I didn't think that would compile on .net 6, but it does!
column[1..]
and it compiles down to a Substring call, and ranges are part of C# 8, so they exist since .NET Core 3.1. But even if the syntax is newer (e.g. collection expressions in C# 12) you can often also use features on older target frameworks if they don't require additional runtime support (and even that can often be retrofitted internally).