Are you looking for something like this:

DECLARE @cmd varchar(2000)
SET @cmd = 'SELECT COUNT(*) FROM x'
EXECUTE (@cmd)

I've not directly tried it but I can't think of any reason why it wouldn't work. There are something that you need to be aware of. The statement is considered another batch. It doesn't have access to any of the variables within the calling batch. I'm also not sure if you would be able to access the Inserted and Deleted tables.

-Mike