In order to set canonical name [CNAME] for a domain from HELM Control panel, you will need to perform below mentioned steps:
1) Login into HELM Control panel.
2) Click on domains.
3) Click on hosted domain from the list for which one need to set the CNAME record.
4) Click on DNS Zone Editor.
5) Click on ADD New button to add CNAME.
6) Enter below mentioneddetails :
Record Name: test
Record Data: www(dot)domain1(dot)com
Record Preference: [Keep it blank]
You will require to wait up to approximately hour for the changes to take place. Afterwards, search made to "test(dot)yourdomainname(dot)com" will take you to "www(dot)domain1(dot)com".