Compare then Copy

Hi,
I have a huge problem conserning 2 * excel sheets that i made.
I have a general list and then a short version which only contains some of the lines from the general list.  Now i need to copy the content of the short list into the general list placing all the data into the right rows.  I have a column called asset numbers which content has a unique identifier which i think could be used to copy the short list rows to right place in the general list.
Pls somebody help me with the solution to this problem.