Paste macro to varible row address

Hello,
I currently have a worksheet with a data base in it. I can call up the data using the vlookup function. i need a macro that will allow me to replace some data in the data base. i know that what row number the data occurs in and the columns remain fixed. so i need to basciall perform a command that will do the following" cell A1=the row number the data is on ie. row 112. so i need to paste to cell G (a1) or g112 from cell A3. cell A1 changes with each data point so im not always copying to G112, the next time it can be G650

thanks