Using Macros to calculate employee hours on a schedule

Can someone help me? I'm trying to write a Macro that can search my spreadsheet for an employees name and calculate the number of hours on the schedule, but I don't know where to start...
For instance I have a range of cells (B57:B78) with all employee names. I would like the macro to go down the list until it finds a blank cell (end of the list) and calculate hours worked.
I have attached my schedule for a visual.
I also relize that I will have to go through and change names so they match the list.
Please let me know if you need any more details.