Edit existing Excel file and read cells

[fmientjes]

From VBA I would like to do the following:

1) Open Excel with a given file (read only if possible)
(A2=value, B2=A2*2)
2) Edit the value in a specific cell (say A2)
3) Recalculate
4) Read the value from a specific cell (say B2)
5) Close Excel, without saving changes

Extra:
If more users run this action at the same time, will it cause problems (or will open read only do the trick?)

Thanks for your help,
Frans