How to restrict a dashboard panel to stop executing when a wild card or asterisk is given in the input field ?

[pavanae]

I have a Splunk dashboard as follows with some input fields. 

Now As you can see above by default the input value for host column is wild card * . Now, If I click the checkbox "show" under Latency validation check it will display a panel below it. 

Now, as a good practice how do I disable executing the search when some one used the wild card in host input as the input will be used as a token for the search. 

I mean only when a valid hostname is given as an input for Host the search should execute for the Latency Validation check. 

Note :-

Here I need the wild card as a default entry for host input as there are some other panels which uses that wild card but I only wanted to restrict the use of wild card to only one particular panel. 

Code can be found below :- 

<input type="text" token="host">
      <label>Host</label>
      <default>*</default>
    </input>
    <input type="checkbox" token="overview">
      <label>Latency Validation Check</label>
      <choice value="true">Show</choice>
      <change>
        <condition label="Show">
          <set token="overview">true</set>
        </condition>
      </change>
    </input>

[VatsalJagani]

Update the token for host filter to "host_temp".

Use similar <change> for host input and use <condition> and with <eval> check if the value contains * (wildcard) or not.

If it does not contain a wildcard set a new token "host".

If it contains wildcard unset the token "host".