Oracle Payables - how to spread a payable invoice over future periods that aren't open in the GL as

 We are using Oracle Financials as below.

RDBMS : 10.2.0.4.0
Oracle Applications : 11.5.10.2

Our problem is that we are trying to enter an payables invoice over future periods.   E.g. the invoice is for $120,000 and is for office rent that relates to future periods, say April to September 2010 and the invoice is dated 1/3/10.   We therefore would like to spread $20,000 over 6 periods, 1-Apr-10, 1-May-10, etc. through to 1-Sep-10.  

We have tried doing this using the Distribution lines but the problem arrises because only April period is open the others aren't yet open.

Any help would be appreciated.