I doubt if i have understood it properly. what i understood is very basic. please find the script below and let me know your requirement in bit more details (if not done).
[Head Count Opening],
[ARC Of Existing Population],
[ARC of Joiners],
[Transfer In HC],
[ARC Of Existing Population]+[Joiners HC]+[ARC of Joiners]+[Transfer In HC] as Total
I looked at the file you provided. Why not let Qlikview total the field in a chart object using expressions, etc on your fields/dimensions? That way all you'd have to do is load your data, create a chart, and select the appropriate settings which would create its own total row.
I've illustrated what I mean in the qvw file attached.
test.qvw 177.2 K