I have a process built in SSIS that loops through Excel files and Import data only from those that include name Report.
My UserVariable used as Expression
In your loop, put a Script task before your first task. Connect those two with a line. Right click that line and set Constraint Options to expression. Your expression would look like this...
FINDSTRING(@var, "Report", 1) == 0
Where @var is the loop iterable.
Only files without "Report" inside will proceed to the next step.
Referencing this exact answer. SSIS Exclude certain files in Foreach Loop Container