You would need to add code into each start/finish textbox to update the values in the Hours/TotalHours textboxes. Forms in Excel do not do auto-calculate. You need to tell it to do that.

As for Account Description, you would need to have the Account Code update event(s) regenerate the rowsource. You probably need to set the rowsource to "" and then give it the appropriate rowsource. I am not 100% sure on this because I am going from memory and I haven't had to work with combo boxes in Excel in a while.