Hi Kuldeep ,
First , some terminology :
The right side pane ( the list box ) is displaying a list of items which match the search string entered in the left side pane ( the text box ).
There are two options :
1. You can do it in the rough and ready way ; go to the VBA Project , and click on UserForm1 ; now , right click on the list box , and click on Properties. In the list of properties which are displayed , click on the right side section against ControlSource , and enter any cell address of your choice , say J1.
Now , whenever you have just one item displayed in the list box , that item will be displayed in the worksheet cell J1.
2. I can provide a SUBMIT button , which when clicked , will transfer the sole item in the list box to a worksheet cell of your choice.
Please let me know.
Narayan