There are two approaches to this problem that I am aware of.

You procedure is passed one string parameter like 'BUY','SELL','CONTRIBUTION' and then the string is split within the procedure into its individual components.

You use a table valued parameter(TVP). Think of this as passing one parameter to the procedure but that parameter is a table containing multiple records. You take this TVP and insert into a temp table. Then you join your results to the temp table.

This thread has some sample code I wrote that you may be able to adapt.

http://www.sqlservercentral.com/Forums/Topic1382201-392-1.aspx#bm1382230

Or search other articles on TVPs.