Recursion question (custom doc flow)

I would like to pick the brains of the SDN hive as to what is the best approach to building a recursive doc flow. The program in question will be passed a Source Document and then have to retrieve both Destination and Source documents where x = source document. The program will then have to "spider" until it reaches no more source or destination documents.

A push in the right direction would greatly be appreciated!

Example of table:

Source Document Source Type Destination Document Destination Type

10002488        YY          10002489             ZY
10002489        ZY          30000920             CLM1
30000920        CLM         10002489             Y1
30000920        CLM         5000047697           Y2
30000920        CLM         5000047698           Y3
30000920        CLM         5000047699           Y4