If you have created a Combo Box control on sheet two to select the name from column A in sheet one, then you can specify the cell link in the control properties. The value in the cell specified will return the index number of the name chosen in the drop down box.
To return the corresponding percentage from column C of sheet one for the name chosen, a separate cell can be used with the INDEX function that populates the prcentage. If, for example, the Combo Box cell link is D2 and the range of percentages in C1:C100, the formula would be =INDEX(Sheet1!C1:C100,D2).
Another approach is to use data validation. Here the range of names in column A of sheet one should have a named range applied. A cell in sheet two can have data validation defined from a list using the defined name. The percentage can then be populated by using a VLOOKUP function on sheet one with an offset of 3 (column C).
