[otrs] Merging tickets from other ticketing systems

Hi ppl, I'm sure that this is answered somewhere in the ML archives, but I wasn't able to find it though :-/ The issue is simple, but before jumping on writing a custom OTRS plugin I want to be sure that the functionality isn't already on mainline OTRS. We cooperate with other organizations but they use RT or others. My (simple) intention is to merge incoming tickets by the foreign ID present in the subject, such as: #193754 I've tried with Generic agent, but I cannot figure out how can it match a variable pattern. Any suggestions or already done scripts/plugins for this ? Thanks in advance ! Roman