12 month rolling totals...

Hello all,
Seems that not only am I a fish out of water, but I'm quite a few miles inland...

Just started with MS Access a couple of weeks ago. Done lots of Cold Fusion and SQL work previosly but those tools are not available to me now. Working in a tabular table. Really basic right now, and I just need a helping hand, a shove in the back, a kick in the... to get me going on something that is probably really simple for you all. I'm just tired of banging my head against the monitor. I need the ability to have been end-user selection a twelve month rolling total. I have a column for month names and a column for VOC emmisions. If the month / date selected is March 2001, I need to output a report that runs from March 2001 to March 2002 and totals the VOC emmissions data for those twelve months.
On the other hand, if the same end-user decides that they need a report from June 2001 to June 2002, then the VOC emmision totals need to be figured for those twelve months and those twelve months only. I have, finally, figured out how to total the whole VOC column, but that is not what is really needed for the report. Since I'm not familiar with the MS Access stuff, and the coffee isn't strong enough, I'm asking for some help. Appreciate any suggestions, comments... or abuse.
thanks,
ron

Report record source set to a query.
For the query, set one column criteria section as; Between[Start Date]AND[End Date]
Set another column as the VOC sum.
User will be prompt for the values and generated report will contain rolling VOC values.

oh well. :(