Loading data into HFM using a GL extract file

We have a GL extract file set up to load data into HFM via FDM.  The GL extract file is a text format and comma separated values and contains entity, period, year, actual, amount, etc.  The data extract is YTD and each month we extract the data out of our GL, JDE.  The problem is when the prior months GL amounts have been reversed or zeroed out in the GL.  Our GL data extract does not pick up zero values so HFM's prior months amounts that should be reversed out remain the same amount as in prior month because a reversing amount isn't picked