frustrated - protecting and tabs

[Mon]

Okay, I'm getting really frustrated with this as I seriously cannot figure it
out. I know I posted last week regarding this, however, I'm really not
understanding how to set up what I'm wanting - so I'm going to be more
specific.
I am doing an expense sheet for employees in a medium sized company. It's a
form consisting of validations, check boxes, and conditional formatting. I
want this worksheet/workbook to be protected. I also would like whoever is
filling the worksheet out to be able to simply tab to the cells that need to
be filled in - and not be able to put anything in any of the cells that
aren't specified for information.
Let me briefly explain how my expense sheet is set up. Up on the top is an
area for the Date and Name (used with Validation), then three check boxes.
The check boxes are titled with categories in which the employees expenses
could have occured. When the employee initially enters the sheet - rows
13-21, 22-30, & 32-40 are hidden. When a check box is checked, the rows
appear. My conditional formatting and drop down list are as follows: in A13
let's say they choose the category from the drop down list of "Miles", then
cells B13,C13,D13,E13 and F13 highlight. If "Parking, etc." is chosen in A13
then only E13 and I13 highlight (to be filled in).
How do I protect my sheet so that when whatever is chosen in column A they
will only be able to tab to the cells that are highlighted.
I am not good at all with protecting or locking or VBA codes.
Can someone please help me?

[mrice]

You are looking at needing macros which work off the change event of the checkboxes and dynamically change the visibility and protection.