Hi
I think you need to read in detail what has been posted here. Chicken and egg I know, but the fundementals of how a script instigates a tool in the C directory is what is being described. Once you have an understanding of this function the wonderful world of Aminet with all its gems become available to you.
You need LHA in your C directory to start with.
I would then set up DOpus4 say and import a button from someone else's config or I can tell you how to set up a button. This way from the DOPus file manager window you can archive and unarchive all your files at the press of a button. Same goes for all the formats. Or use one of the DeCrunching apps from Aminet.
I do understand the chicken and egg thing.. but once over the hurdle you will be flying... LHA... classic Good old Stefan Boberg.
scuzz
http://www.commodore-amiga-retro.com
