Selection routine

[Savagefool]

SO I have a table like this:

Assume Tidal Time is column A, Tidal height column B

Tidal Time	Tidal Height
00:00:00
01:00:00
02:00:00
03:00:00
04:00:00	4.5
05:00:00
06:00:00
07:00:00
08:00:00
09:00:00
10:00:00	2.1
11:00:00
12:00:00
13:00:00
14:00:00
15:00:00
16:00:00	4.5
17:00:00
18:00:00
19:00:00
20:00:00
21:00:00
22:00:00	1.9
23:00:00

<tbody>
</tbody>

What I need is a selection routine in excel-VBA like this:
Find the last non empty value (In this case 1.9)
Select last empty Value.
Select each cell up till the next non empty value. (In this case 4.5)
Use the following code to trend:

Selection.DataSeries Rowcol:=xlColumns, Type:=xlLinear, Date:=xlDay, _
        Trend:=True

Select that cell again (4.5)
Select each cell up till the next non empty value (In this case 2.1)
Trend.
Select that cell it finished on (2.1)
Select each cell up till the next non empty value(In this case 4.5 at the top of the table)
Trend.

That's pretty much all that needs to happen.
Can any shed some light on the process for this? I keep getting confused. It doesn't help that there are many different ways to do it either. Thanks in advance!