Combo box help

Hello

i am a newbie in Macro, i need help to create a combo box from excel which is link from another data sheet, that everytime i choose one data in on combo box the values will show to another combo box.

this is my Data Sheet
Date Month
1 January
2 February
3 March
4 April
5 May
6 June
7 July
8 August
9 September
10 October
11 November
12 December


this is my validation sheet.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 this is my validation data in Date
=OFFSET(Header,MATCH($C$4,Date,0),0,COUNTIF(Date,$C$4),1) this is in Month

Date Month
2 February

i wanted to use the combo box because i have a big data file, i think it is better to use so i can type directly and combo box can auto type or something..

please help... thank you in advance.