Use the OnModeChange trigger to perform a script when the user enters find mode. Have the script use set field with get ( AccountName ) to enter that info.
Use access privileges and a "lock" expression to control the users access to the records. When any find is performed--both by script or by hand, all "no access" records will be automatically omitted from the resulting found set.
See "Editing record access privileges" in FileMaker Help and check out this particular sub section: "Entering a formula for limiting access on a record-by-record basis" for a description of how to set this up.
I will give it a try. Thank you very much