using a flag file in a batch

I know this isn’t really a Windows question, but there’s no Dos subject.
I need to write a batch file that will check a flag file for a version number, compare it to a version on a server directory, and if it is older than the server I will need torun a separate executable.
Example…
C:\update.txt contains “1000”,
F:\update.txt contains “1001”,
so batch file runs F:\update.exe and also copies new update.txt file to C:
I know this is possible, but it’s been a LONG time and I could use a hand.