I think that once they've moved, you wouldn't be able to determine where they
came from.
But did you try the suggestion in this:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;838910
Controls move to the left of the worksheet in Microsoft Excel 2002
WORKAROUND
To work around this problem, configure the positioning properties of the command
button to the Move and size with cells option. To do this, follow these steps:
1. Right-click the command button, and then click Format Control.
2. On the Properties tab, click Move and size with cells.
3. Click OK.
By default, this option is set to the Move but don't size with cells option.