I forgot to mention our server version is FM 10 and uses .fp7 file extension
Is the launcher file a FileMaker file? (there's more than one kind)
If so, you should be able to open the file and update the external data source reference found in Manage | External Data Sources. You should be able to simply edit the IP address in this window.
Thanks for the response. Thats what I thought but when I open the launcher I gat an error that it cant find the database and the Manage option is grayed out.
You need to open the launcher without it performing the start up script. You may need to hack it open if you don't have FileMaker Advanced. With Advanced, you can launch FMP advanced without opening this file, then enable the script debugger and use Open from the file menu to open the file. WHen the opener script pops up in the debugger, click the X to halt the script. This should leave the file open so that you can update the data sources. You may have to hold down shift or Option while opening the file to get it to ask you for a full access password if you have that file option set.
You may also be able to press Esc or command period after you dismiss the "can't find the file" dialog to abort the script.
If you have to "hack" it open. Create a small FileMaker file and use Perform Script to perform a script in the launcher file. Choose any script other than the script that performs when the file opens. (But there may not be another script to perform...)
If all else fails, create a new launcher file. That isn't really that much more work than updating the IP address in the external data sources window.