Griff's code is ok, it could be made better, for example, if your combo box values simply were the alias names used for the tables you wouldn't need the CASE statements, simply SELECT (cbo.VALUE) on the condition USED(cbo.VALUE).
Griffs Code has one prerequisite, that the tables you search already are open (USED), for example by being put into the data environment of a form or by USE statements in the form load or init. You could already have them open to display them already before searching, but you might also want to open a table at the time it is really searched.
Then you may want to do a SQL query based on the search term, which does not only locate one first result record. That means LOCATE is not the only and surely not the best way to search a table, though it is a simple approach, it might not be as highly optimised as SQL can be. With SQL you also wouldn't need to do the preparation step to open a table, the SQL statement can do that simply based on the file or table name, eg [tt]SELECT * FROM (cbo.Value) WHERE somecondition INTO CURSOR crsResult NOFILTER[/tt].
It's too undefined, what you want to have, so this may hold as a first solution approach, but it's not the only way.
You ask for very basic things and seems to have not much programming experience, that's why I would conclude this way: Don't think you can learn VFP programming by solving simple tasks, that's asking for detail solutions to problems you wouldn't even have, if you had a foundation of knowledge about how to do things in VFP on a much more general level than how to use each single function or command.
Learn a few basics, watch some resources like the solutions.app coming with VFP, which you find opening the task pane and clicking on Solution Samples. Then there are books:
and videos
Bye, Olaf.