Adding Text to Text Files [Batch Script]

Given two text files:
C:\INFO.TXT
XXX.XXX
XXXX_XXXX_XXXX_XXXX_XXXX

C:\HISTORY.TXT
TIMESTAMP
XXX.XXX
XXXX_XXXX_XXXX_XXXX_XXXX

TIMESTAMP
XXX.XXX
XXXX_XXXX_XXXX_XXXX_XXXX


I need a batch file / script that is able to do the following:
- Append a “.F53FLIN” to the end of the second line in the INFO.TXT so it looks like “XXXX_XXXX_XXXX_XXXX_XXXX.F53FLIN”
- Add 4 lines in the HISTORY.TXT file, a timestamp (when the script is run, now()), and a copy of INFO.TXT with an empty/blank line following it
So, in essence I am trying to write a script that adds the .F53FLIN to the INFO.TXT (second line) and a TimeStamp+INFO.TXT+BLANK LINE in the HISTORY.TXT (append to the end).

I have tried a few attempts but nothing is coming out even close to right, was hoping someone could help solve the problem.
Any hints, ideas, or help would be greatly appreciated,

Can you please
1-show your code
2-show sample input and expected output

LinuxPenguin: I don't have any working script/code, I can't seem to figure out how to append to a line nor can I figure out how to add the information into the history file.

A concrete example of INPUTS:
C:\INFO.TXT:
1.1
IBb_1.1_LM400_JA1.2.3_1A

C:\HISTORY.TXT
02/01/2006 8:33am
1.0
IBa_1.0_LM399_JA1.2.1_1A

02/20/2006 8:33am
1.1
IBb_1.1_LM400_JA1.2.3_1A

(the contents of the files are presented below the filename)

A concrete example of OUTPUTS after the script is run:
C:\INFO.TXT:
1.1
IBb_1.1_LM400_JA1.2.3_1A.F53FLIN

C:\HISTORY.TXT
02/01/2006 8:33am
1.0
IBa_1.0_LM399_JA1.2.1_1A

02/20/2006 8:33am
1.1
IBb_1.1_LM400_JA1.2.3_1A

02/26/2006 1:32am
1.1
IBb_1.1_LM400_JA1.2.3_1A.F53FLIN

That's it... hope it helps....

Well the problem is, we have an unofficial policy here: if you haven't shown proof of trying, it's considered homework, and we don't do homework (we can help you with parts of it though).