lookup(var1,var2)

This function uses the values of the second argument as row numbers, and returns the value of the first argument in the row number specified by the second argument. The first argument can be of any variable type. Note that both arguments must be variables. For example, suppose there is a variable called !key!, and its values in the first four rows of the dataset are 3, 27, 49, 31; if you type the transform

$lookup(!flow1!,!key!)

then the results in the first four rows of the dataset will be the original values of !flow1! from rows 3, 27, 49, and 31.