both SQL and Oracle support pattern matching for any character:
select * from YourTable
where YourColumn like '%H_M%'
SQL supports a type of regular expression like this:
select * from YourTable
where YourColumn like '%H[a,e,i,o,u,A]M%'
select * from YourTable
where YourColumn like '%H[^e]M%' --<your example NOT E, but any other letter:
where Oracle requires you to use the regular expression object to do the same:
http://docs.oracle.com/cd/B19306_01/server.102/b14200/conditions007.htm
does that help?
Lowell