VBA for Word Timesheet – Super User

I am making a timesheet for my employer, and it needs to be in a Word table.
Rows contain the following cells, going across:
Start Time (clock time) / Lunch Duration (# minutes) / End Time (Clock Time) / Daily Hours (Total hours and minutes).
I have been able to come up with a formula that automatically sums the Daily Hours on each row as I type it.
{=sum(f3,f4,f5,f6,f7,f8,f9,f10)# “0.00” }

I would like to have the Daily Hours column automatically populate as data is entered on the Time End cell, and then have this number be added in to the sum at the bottom. So for example, on the first row I enter 8:30 as the start time, 30 as the minutes for lunch, 17:00 as the end time, and when I finish typing 17:00 and tab out of that cell, have Daily Hours now show 8.00 for total hours, and have that value auto show up in the sum at the bottom as well.

I think what is confusing me is trying to mix clock time, and numeric hours and minutes.

All assistance appreciated.

Zane