Use index property.

Ex:
Browser("title:=.*").Page("title:=.*").WebList
("name:=account type","index:=8").Select "value"

HemaKumar has given your answer but has written the code 
for WebList by mistake.
You can use this:
Browser("title:=.*").Page("title:=.*").WebCheckbox
("name:=account type","index:=8").Set "On"

We Can check the webcheck box by using its Index number in 
the application.
Browser().page().Webcheckbox("Name:=Chekbox name","index:=9 
or 8").select

               OR

We Can also Add all the check boxes To the Object 
repository based on the Index numbers and select them in 
the Code by writing
Browser().page().webCheckbox().select "ON"