Key stroke event to trigger action on ActiveForm Text Field

I've got a search string input field, an ActiveX text box,  at the top of a worksheet.   The search works fine.   Right now I trigger the search by a double click on the text box.  I'm looking for a way to trigger the search with a key stroke, like a tab key or something, so that when I finish typing the search parameters, I don't have to reach for the mouse.

I tried adding a second, blank field which I can use to click on, to trigger "Lost Focus" on the search field, but that's still a mouse move.

I tried using the change event on the search field, with a control value (@) to indicated "I'm done entering search parameters", but it seems to loop all over itself when I try to remove the @.

I basically gave up on the ActiveX and built a little modal form for this purpose, however, I'd still like to know if / how it could be done with ActiveX on the worksheet.

Any help with this would be appreciated.