How to find 1st column index

iss there any activity to find 1st column index?
As we have activity to find last column index

@Doonline ,

Are you looking for excel column index.

First column index would be 0 in most of the cases.

yess excel datatable index,
yeah we know but i need to find it 1st column index.Bcoz 1st column can be present in between the sheet