Hello I need help with a Sumproduct formula.

I have a column with dates another with times and the last one with number of calls
Example
A B c
1/2/2013 12:00 AM 3
1/2/2013 1:00 AM 4
1/2/2013 2:00 AM 1
1/2/2013 3:00 AM 6

I need a Sumproduct formula tha will add calls between 1:00 am and 3:00 am Only
Based on date and time look ups. I can not use the SUMIFS OR COUND IFS Because Im usint and external spreadsheet as my data source and it will not update unless you have the data spreadsheet open. So im stuck using a Sumproduct.