Excel 2003 Please Help With CONCAT Dilemma

Hello,
I need one column to show the following text: prxyz,(Data1 here),0699,ABCD(Data2 here),xxx

Data1 is in Column A and Data2 is in Column B.

The format of data1 needs to be 5 numbers (sometimes beginning with zeros).
For data2, they need to type in data that's 9digits long and ends in a letter. If they enter 9 digits only, the letter needs to automatically be substituted with 0 (zero).

So for example if I enter '123' in A1, '12345' in A2, '123456789' in B1 and '987654321Z' in B2, it needs to come out as:

      A           B                              C
1 00123     123567890     prxyz,00123,0699,ABCD1234567890,xxx
2 12345     987654321Z   prxyz,12345,0699,ABCD987654321Z,xxx

I've formatted col A out w custom format 00000 for it to always display 5digits. But I'm stuck on Column B and C.

This is what I've come up with but it's not correct: ="prxyz,"&A1&",0699,"&"ABCD"&B1&",xxx"

Please help?

(I'm clueless about macros so I'd really appreciate it if I can do this just using Format and Functions.. I hope this is possible?)