Let review the typical situation: you have 2 lists of database values, and you need to merge them into single list which contains values from both lists.
xlCompare has a command which merges lists of values. To use it you need to compare 2 lists of data you have. Put them on 2 different worksheets and compare.
On this image we've highlighted command which joins 2 compared lists:
This command is applicable to single pair of compared worksheets only. It is visible on the toolbar if you've selected a node under "sheet" node. In this example - old - new.
It joins two lists with database values and puts results into the left sheet. If you need to create a merged list on the another worksheet - you can repeat the operation after switching left and right panes.