Anything that you can set up manually in a find can also be scripted. One way is to set up a group of global fields for the user to enter search criteria while in browse mode and then a script can take the data in these global field to set up one or more find requests that find records.
An "OR" type find can be set up with a script that uses New Record/Request while in find mode to create additional requests or your script can perform a find for the first criterion, then return to find mode, specify the second criterion, but use Extend Found Set instead of perform find.
For examples of scripted finds that use these methods see: Scripted Find Examples
Thank you! It worked perfectly!!!