How can I perform a *text* find with a script??

I knwo i can enter the find mode and put the (*) to search a word wherever it is, but how can i do this with a script?? I cant go into find mode cause its a field where you have to write and press enter to perform the find.

Here is a sample script:

Go to layout you wish to perform find

Enter find mode (do not pause)

set field [field name, "text to search"]

perform find