Image bulk load/Attachment ID

Hi there,

First post after some frustration, and I do know that I am probably missing something; please do not flame me.

After loading many images, I now need to assign them to many alreadty loaded e-commerce products. So far (and I know that this would probably be breaking the rules) I have worked out that I can update (SQL) the POST_CONTENT column in the WP_POSTS table. The only problem there is that I do not have the attachment_id to put into the string. In addition, to denote the thumbnail, I would need to INSERT (SQL) into the WP_POST_META table and entry with THUMB_ID and the relevant ATTACHMENT_ID. This would appear to do the trick. the only problem is that I need to be able to (in bulk) retrieve a list of ATTACHMENT_IDs i.e. using the jpg name use it as a key to find out the ATTACHMENT_ID.

I am of course sure that there will be a simpler way, but any help appreciated.

Best regards