Try something based around an if() like the one below:
=count(if(End_Date>=today() and End_Date<=$(v_Future_Date),Contract_Number))
The syntax isn't checked but the principal should work - it will count all contracts between today and the date in your variable 'v_Future_Date'.
Hope that helps,
Matt - Visual Analytics Ltd
Qlikview Design Blog: http://QVDesign.wordpress.com