Merge two files with similar column entries

[pratapsingh]

Hi , I have few files which contains user name and data transfer rate in MBs and this data is collected for year and for each month report is saved in 12 different files I have to merge all the files to prepare the final report Files are as below

Filename1 : January

#User Name           #Data Transferred

A. Paul                       300004
Jason                        600000
Mayur Pandey             40000
Kelly H                       459000
Ryan M                       349000

Filename2 : March 

#User Name           #Data Transferred

Senthl V R                  600000
Mayur Pandey             40000
Kelly H                       459000
Pratap S                     349000
A. Paul                       300004

Similarly I have 10 more files I have to merge all these files to one file and final output should be like below one:

Final Report:

#Username     #January      ....       #March ......... #December     
+#Total

A. Paul               300004                300004           Not avail
+able 600008
Pratap S        Not availanble            30000            32000      
+     7899887
Kelly H               459000               459000            459000   
+     3424448274
Mayur Pandey      40000                400000            400000       
+  242424442
Senthl V R           Not available       600000            34544      
+    53546464
Jason                 600000              Not available     3434343   
+    43434355

I need a perl script to automate this rather using excel or doing manually . These reports are generated monthly and names are not stored in sorted order. Names are stored in recent user who has used data transfer facility. And also there are occasions when a user have not used data transfer at all for particular month in this case name of the user will not appear in monthly report file. In this case I have to add not available in the month name column. Thank you