If you want to work with the file in Excel, and use the Python to just open it in Excel, I prefer subprocess.Popen() rather than subprocess.Call().
To open the file in an specific sheet, you should save the workbook open in the selected sheet before opening it in Excel. If your file is a .xlsx file the best Python module is 'openpyxl' (in my opinion of course).
The following code worked fine in my machine (Windows 10, MS Excel 2016 and Python 3.6.3):
import openpyxl
import subprocess
filename = "<Full path to file>"
wsToOpen = "<Worksheet name>"
# Openthe xlsx file in Python
xlsx_file = openpyxl.load_workbook(strCamArq)
# List with all the worksheets in the workbook
lst_worksheets = xlsx_file.get_sheet_names()
# Change the active worksheet in the workbook
xlsx_file._active_sheet_index = lst_worksheets.index(wsToOpen)
# Save the workbook open in the chosen sheet
xlsx_file.save(filename)
#Open the workbook in MS Excel
subprocess.Popen([filename], shell=True)
Then, the opens the file in MS Excel exactly in the sheet specifyed in 'wsToOpen'