Mapping of Zoho CRM Lookup field to CRM

Mapping of Zoho CRM Lookup field to CRM

Hi, 
I have created a Zoho CRM Lookup field on a form for a client. The population of the field works great in the form however I cannot seem to get the data being entered in the form back into CRM. 

For example, the form is for new clients to fill in their personal information which creates a new Contact in CRM. The lookup field is the company name. The user would need to look up their company name when completing the form, how can I get this company name to map back to CRM so the new contact is attached to the company? 

Thank you 
Hayley