Excel 2007 : Loop to check if date is between two dates from 2nd workbook and loop until true

I need to write a macro that will do the following.
- Check whether a start date from first file "Summary" is between two dates in second file "Dates".
-Loop through dates until it finds a set that it is inbetween.
-Once it finds a true statement, I need it to return the value from the "Dates" file into the cell for the corresponding Job.
- Repeat this for every Job and Date combination

I am getting stuck on referencing another workbook in a VB IF statement and looping statements always seem to get the best of me.

Please help. Thanks!!!