Populate a field based on the value on another field from a different module

Populate a field based on the value on another field from a different module

I have 2 Custom Modules (1 and 4). I am trying to fetch "Customer Warranty Expires" field value of "M odules  1" to populate the same field value in  "M odules 4 "   under "Products 01 - Warranty Expires". For this purpose, I am using the value entered by the user under text box "Products 01 - Warranty Expires" in  "M odules 4 " which is the unique value under  "M odules  1" that is specified under " Device IMEI" field of  "M odules  1" .

I used Lookup Feild for  "Products 01 - Warranty Expires" and used the below code which worked. But Zoho limits the total Lookup for a module to 4 which does not solve my problem as I want to have 5 Products in the same Module.

void UpdateRMmodule (int rmId,  date cwe )
rmIdStr=input.rmId.toString();
mp=map();
mp.put( "Products 01 - Warranty Expires",input.cwe);
updateResp = zoho.crm.updateRecord("CustomModule3",rmIdStr,mp);