compare set of rolling months

[#1]

I would like to compare a set of month with the same set of month -1.

ie. if I highlight the months Jan2014-Feb2014-March 2014, I would like to have a column next to the previous where I have the sales value of Dec2013-Jan2014-Feb2014.

Year
2011	2012	2013	2014
months
jan	feb	mar	apr	may	jun	jul	ago	sep	oct	nov	dec

	sales
	jan '14	feb '14	mar '14	dec '13	jan '14	feb '14
client
client
client
client
client
client

if I highlight 5 months I'll have the comparison Jan'14/Feb '14/Mar '14/Apr '14/May '14 VS Dec '13/Jan'14/Feb '14/Mar '14/Apr '14 and so on...it is possible (and if yes, how) to do it through set analysis or I need to write a macro?

[#2]

hopefully this will help...sorry for not being clear enough...

[#3 · Accepted solution]

aha ...

[#4]

Let me know if you like my v2 example

[#5]

you rock man!!!!! thank you so much!!!! really helpfull!!! that's what I was looking for!!!

[#6]

I would like to be able to do similar things with my income in a bank account

[#7]

A little bit optimised ....