Batchfile to move files to a specified folder based on content

At my workplace I receive automatic emails containing textfiles as attachments. only a small portion of those emails is intended for me, the rest can be moved to a "trash" folder. everyday I am spending a lot of time opening those ascii files and looking wether a specific word occurs in them.
Since the email program saves all attachments from this sender in a folder, the only thing I would need, is a

Batchfile which parses all the files in a directory and moves them to another folder, if they dont contain a specific word.

..the whole thing is probably very easy for someone with experience in writing batchfiles, a two liner or so.. but I tried for several hours and I dont manage to do it. the batchfile syntax is too cryptic....

can anybody help me?

cheers
aljazir