Automatic cell fill in

Hi all

I used to work with a spreadsheet that had dated running 1 and down and then categories running A accross. It was to calculate money for each category which there are over 25 of. Accross the top for each category i used a number 1-25 for them all, so all i had to do is go into my second column and enter the number that corresponded with the category and the amount would go there to save having to tab accross hundreds of time. Can anybody tell me what the formula for that is??

I hope I have explained enough??

Cheers! :-)