At last my application is working as it should, maybe something to do with the abundance of support above. 
The solution was fairly straight forward in the end.

Not getting anywhere with this app.

I have re attacked it using the DDE plugging and have got the data sometimes entering excel.
Sometimes on starting the ASDL it connects to my PC speaker, and it bleeps as data comes in which is awful, try restarting and it stops doing it.

Note I am using office 2007!
If I set up to open a new workbook there are no Calls entered EG "=asdlog|DDESrv!srviDATA"
So I tried using templates, XLS fails to open anything "my guess is 2007 is trying to create an XLSX from an XLS and failing, the file is there, ASDL can't open it and if I open it, it is un writtable.
If I use XLSX I can not use the code from your site or any code for that matter.
If I use XLSM (macro enabled, once again it fails) XLSM is not one of the defined files for opening so I used all files and selected it.

If I can get this app working and get it to repeatably open and work, I''l happily buy it and the associated apps, Emulator, port monitor etc (which I think are actually v good).

 
After playing around at home it is now almost working right.
It does not appear to react to changes in settings until after it is shut down and re opened, I can live with this.

1st cell written to does not affect cell size but second write and each after adjusts the height of the cell, wrap i guess.
I adjusted the Column width on A and B, then protected the rest of the sheet.
Ok so it's now stating in the right, cells are staying the right size and it's performing the move, 1 cell down each time as required.

This has now flagged up another error though in that it does not save the last cell position after restart and overwrites the existing date.
I have tried saving changes to both registry and also an INI file.

Just tried this at work,
Different PC (home XP64 excel 2002) work XPpro 32, Office 2007 (i think as someone pinched my "about" menu option.

Downloaded software from your site, did not transfer from home.

Same result here, each succesive read places the data in the same cells. A2 and B2.
However it appears to read each time without problem.

Data is coming from your data emulator, Random Text as below.
<-30/08/1116:31:20  0200:05:10 3177990     
<-30/08/1116:31:24  0200:15:29 3098907     
<-30/08/1116:31:28  0200:05:44 9108999     
<-30/08/1116:31:32  0200:10:44 1989663     

Many thanks Arthur, I am at work now (not home as before) so I will download another copy and try it from another PC.
I will let you know if it works, Home is not really important but may help someone else if we can identify what is happening.

I'm using the com port data Emulator, no problem and this is being read in Advanced serial Data Logger 3.9.7.713 no problem.
which opens an excel book and sheet and inserts the data.

Full data packet|FULL_DATA_PACKET|1|0|A1|50
Data packet|DATA_PACKET|3|0|C1|50

both enter data but strangely into A2 and C2.
the next data parsed overwrites A2 and C2 and continues to do this in all modes except reverse move where it appears to insert a cell and the earlier results shift down each time.
What I want is for the data to be appended on each result.

I tried the excel export proffessional and it works providing i don't look at the file, unfortunately my application requires we look at the file to see the test results each time.

Thanks.