Thanks Mumps1. I can't really attach the file as it is all sensitive information and I would be breaking the law.
I could try to explain things a little better.

First sheet, column A, row 2 - Subnet start, column A, row 5- first IP address. The IP Addresses go down to row 296.
This is repeated in column F with Subnet ends.


Second Sheet - same as first sheet but IP addresses go down to row 371.

Third sheet - column B starts at row 5 and goes down to row 186 - it is surrounded by text.
There is then a second list of IP addresses in sheet 3 on row I.

4th Sheet - Column A1 to A48 text and IP addresses I.e.(Changed for data protection) "net subnet 10.145.215.8 255.237.255.1 include"
Column D1 to D48 - List of IP addresses.

5th Sheet - same as first sheet but ends at row 337.

6th Sheet - same as first sheet but ends at row 355.

7th Sheet - same as first sheet but ends at row 307.

8th Sheet - 3 lists of IP addresses surrounded by other data in columns E, H and AD from rows 1 to 6933.

9th Sheet - same as 8th sheet.

10th Sheet - same as 8th sheet.

11th sheet - same as 8th sheet.

12th sheet - same as 8th sheet.

Hope this makes any sense at all!