Questions about arrays

["Wang, Andrew via Tech-talk" <tech-talk at aps.anl.gov>]

All,

I have two questions pertaining to the array records in EPICS 3.15. 

1. Suppose I have an analog input array or waveform record of size 5 that contains the values 1, 2, 3, 4, 5. Suppose I want to replace with the fourth element. Based upon what I've read, it doesn't seem like subArray is a viable choice. I've also tried to use caput but to no avail. Any recommendations other than using aSub?
2. Suppose I have eight individual analog input records and I want to "concatenate their values" and store the result into an analog input array record. I'm thinking about using either aCalcout or an aub routine. Are those valid options and if not, what are alternative options I should explore?

Thank you!

Andy