Find Reports w/ Specific Filter Conditions (critera)

A user has created probably hundreds of separate reports with varying Filter Conditions. Now I have been asked to updated all reports with a filter

Region / is one of / PN or RM

and replace it with

Region / is one of / MP

Is there a way (a) to do this search and replace on a batch of reports at the same time? Preferably all reports within a specific Workspace? OR (b) at least use a search to identify any reports containing that Filter Condition so I can manually update the Condition in each report?

Going through each report could take an eternity because of how many reports are in the Workspace. Thank you in advance for any assistance.