In general you'll be better off reading the Excel file and doing any search/selection in memory discarding what you don't need instead. There's no builtin Matlab function to do other than read a rectangular section form a Matlab file, so other stuff would needs must be done via COM using Excel syntax to do the operations and that is an Excel programming question not Matlab (other than opening the ActiveX connection).
The one way otherwise would be to have created a name for the location in the Excel sheet; xlsread will accept a name as a RANGE argument.
