If you mean the values are already displayed and we wouldn’t need to Click on the Dropdown and select the required value. Then instead of Select Item activity, we could try with a Click Activity itself.
We can check on the Selector of the Click activity, and find the attribute which contains the value. Replace it with the variable which contains the value from excel being retrieved.
Use ui explorer and then identify one of the list element and try using innertext which contains the name you want to click…you can include a variabe in place of that by right clivking on the name and then select the value you want to add
the selector should look something like this
<webctrl tag='LI' innertext='ABC' />
This selector that you identify can be used in a click activity to click on it as you added variable everytime it clicks on the related variable name