Need custom field that pulls the assignee's total Sprint hours

[Matthew_Schulz]

Hi,

I'm in need of a scripted field that calculates the sum of the assignee's Sprint work hours. (Ex. Jeff has 5 Stories with 6 hours on each for Sprint 1. There's a custom field on a "Capacity Issue" that will calculate those hours on the story automatically, based on the issues assignee and Sprint, to tell me that he has 30 hours of work. Then have the number populate a custom field. 

So I need:

1. Get hours of work based on the Assignee and Sprint of the "Capacity Issue".
2. Populate a custom field with a number.

Thanks for any help!