This script can be used to change an already open Open/Save dialog box to another file/folder. To use it, first open the dialog in your application, then launch Quicksilver, select a file/folder in the first pane, then the script in the second pane.
See AppleScripts for more information on using and installing AppleScripts. See this thread for discussion on this script in particular.
using terms from application "Quicksilver"
on get direct types
return {"NSFilenamesPboardType"}
end get direct types
on open files theFiles
set filePath to POSIX path of item 1 of theFiles
tell application "System Events"
set theApplication to application processes whose frontmost is true
set target to item 1 of theApplication
set target to a reference to front window of target
tell target to keystroke "g" using {command down, shift down} -- Activate goto field
delay 0.1
if ((count target's sheets) > 0) then set target to front sheet of target -- Open panels use a sheet
tell target
tell sheet 1
try
set value of text field 1 to filePath
delay 0.5
click button "Go"
on error theError -- Carbon apps don't support setting the field directly, so type out the path.
keystroke filePath
delay 1
keystroke return
end try
end tell
--
end tell
end tell
end open files
end using terms from