First read the first column into dt1 and second column into dt2 using 2 read range activities
Use add data column and add a column sum to dt2 and another column to dt1 and match both column types are to be double
Use a for each row in datatable and loop dt1
Inside the loop use an assign activity dt2.Columns(0).Expression = "[ColumnNamedt2] - " + Cdbl(currentrow("Columnnamedt1").ToString)
5.use another assign to sort the table dt2.AsEnumerable.orderby(function(x) math.abs(cdbl(x(0).Tostring))).CopyToDaTatable
Now update match column of dt1 in assign
`dt1.Columns(1) = cdbl(dt2.Rows(0)(0).Tostring)
Use remove data row and remoce the first row in dt2
Now at the end you will have all the matched records in dt1