Set Lookup value from Single Line input value

Set Lookup value from Single Line input value

Hi,

I wonder whether it's possible for Lookup value to mirror value filled in Singe Line value ?

I'm trying to build a lookup function for certain value, it works, but when I fill the data, it shows all the records which will contain private information and based on information I got, we can't hide the shown records. So I just wonder if Lookup value could mirror the Single line value while I hide the Lookup field.

I tried using input.Lookup = input.Singe_Line; but doesn't work because BIGINT and String.

Any advise ?