If you don't care about the delimiter and only want that specific pattern then try this:
with mydata as(select q'[A<1,?,'providerInfo'='0003\\370\\3370288.dat','storageProviderName'='ExtShared','subProviderName'='Default'>]' mycol from dual)select replace(regexp_substr(mycol,'[0-9\]+\.[a-z]{3}'),'\\','\') from mydata/
Open in new window