Unfortunately since you're not on 12+, you can't use the base directory container management window to do this the easy way.
You will need to calculate the new file path, while looping through and updating each record's path.
This might help:
your script would look something like:
Set Variable [ $old ; GetAsText(table::container) ]
Set Variable [ $new ; Substitute($old ; "filewin:/G:/" ; "filewin:/Z:/" ) ]
Insert File [ Table::container ; $new ; "as reference" ]
Go To Record [ next ; exit after last ]
There might be an easier way but I haven't dealt with a transfer in <12 for a few years now.
This does require the container field contents to be in both places while the transfer takes place.
Also, as usual, make sure you backup your original FM7 file just in case.
As Mike noted, there are easier ways to do things in the current version of FileMaker. Also, FileMaker has deprecated supported for version 10 and announced the depreciation of support for 11. If your data has value, and if nothing else but for security reasons, you should be looking to upgrade.
Some of the new container support features includes previews that only pull across images necessary for the size of container, thereby making container fields of pictures load MUCH faster. And the whole Remote Storage in FM 12/13 integrates so well and includes additional security features like encryption. Between performance and security, it has been nicely improved upon by FileMaker.
Best of luck with the scripting. Make sure the GetAsText returns what you need in the reference (you might only need one line of it and use the GetValue function to do that). Let us know if you have problems implementing the loop and well help out.
I wrote following script as per you Mike. Thanks a lot mate.
SCRIPT Update FilePath
Go to Record/Request/Page [ First ]
Set Variable [ $old; Value:GetAsText ( Table::Document container ) ]
Set Variable [ $new; Value:Substitute ( $old ; "/old folder/" ;"/new folder/" ) ]
Insert File [ Table::Document container; “$new” ] [ Reference ]
Go to Record/Request/Page [ Next; Exit after last ]
Note: Make sure while running the script the new path is accessible.