To put values in to textboxes it is the same as if you had created the SQL query on the fly:
Dim mCommand As SqlCommand = New SqlCommand
.CommandText = "MyProcedureName" 'instead of "SELECT * From MyTable etc.
.CommandType = CommandType.StoredProcedure 'Instead of Text
'if I want to pass data in use parameters
textbox1.text = mCommand.ExecuteScalar() 'assuming a scalar value is returned