In Zoho Expense you can delegate another user to create, submit and approve expense record on your behalf. Lets take a look how you can achieved this in Zoho Expense.
To begin you are require to add delegate under setting:

You may delegate access to selected user and you are able to specify start date and end date (end date can be empty):

You may select access type:
1. Submit access
2. Approve access
3. Submit and Approve access
Subsequently you may proceed to Grant Access when you have complete the set up.
You are able to edit delegation setting should you need to do amendment:
The selected user for the delegation will be able to view delegation status:
Subsequently would be able to switch profile to perform delegation exercise on behalf:
Upon switching profile, delegate user will be switched to other user window/view and be able to switch to own window/view:
Delegate user will be able to perform expense exercise on behalf based from the delegation access type:
Happy trying :)