Do you need to group by month and then by movement code or movement code and then month? If you can group seperately, this will be easier.
For the date field:
Create a group on ITMMOV_MOVEMENT_DATE. In the Group Expert after you select the field, change the value under "This section will be printed" to "for each month". You can then format the group name to show the month name for the date field by right-clicking on it and selecting "Format".
For the Movement code:
Create a group on ITMMOV_MOVEMENT_CODE. If you want to display the 'W' first, tell it to sort Descending. Otherwise leave it at the default of ascending.
-Dell