If Report B has prompts for YEAR and MONTH, you should be able to pass the filter values from Report A to Report B. There are some limitations depending on which version of WRS you are using. Specifically, you cannot pass values for numeric expressions in version 4.2.
Here is a sample for passing prompt values to linked reports written for version 3.1, with some updates for 4.2.
Report B has Year, Month and Country prompt(all alphanumerical), and they are all
shown in report linking dialogue, but I can only select an entry for country prompt.
But I guess in your SAS link the note says it's not possible:
"Notes on Report Linking Via Prompts
* If you hide a category that is being used in a report linking prompt, then the prompt association is removed. The report link will still work but you will have to complete the prompt window before the target report is rendered."
The category Year and Month are hidden, they are only used for section filter.
I guess it's a problem with multiple entries for section filter(like Month IN '01, 02, 03'),
I think right now it's only possible to pass one entry to the linked report.
What I would have is a link (to the stored process, passing the parameters) defined within the data table itself, then select the 'Display as Hyperlink' button in Information Map Studio (similar to my post on doing this for formats: http://sas-bi.blogspot.com/2010/01/custom-colors-on-categories-in-web.html). Then the data cells should link to the Report B passing the information you require.