Thank you for your post.
Pasting the information into a field is not difficult. However, you will need to create a script that evaluates the information, searches, and if not found, then add a record.
Create a Text field, PASTE, with global storage. This will be used to evaluate the pasted information.
Create a script that does the following:
Set Error Capture [ On ]
Set Variable [ $info ; <calculation to retrieve search information> ]
Enter Find Mode 
Set Field [ <search field> ; $info ]
Perform Find 
If [ Get ( FoundCount ) = 0 ]
<put your Set Field statements here>
Show Custom Dialog [ "Record already exists" ]
That is, find the search criteria in the pasted text and put it in the variable $info. Then, go into Find Mode and put the contents of $info into the field you want to search by and perform a find. If no records are found, then you do not have an existing record, so add a new record and put the information into the appropriate fields. Else, if an existing record is found, then display a dialog box that the record already exists.
Finally, attach this script to a (VERIFY) button on the layout.
If you need clarification for any of the above steps, please let me know.