Lookup and History

[tlxforceteam]

Dear All,

I have created into Account a custom field (say it "acc_custfield") and enabled on this field the history tracking because the value of this field can change over the time. Moreover, I have a custom object that has a lookup relation to the Account. Really, the relation to the Account depend also on the value of the acc_custfield. So for example an Account can have until now acc_custfield = XXX and then I change acc_custfield = YYY. The history tracking should track this change.

Now I have to upload my external data (that I have on my previous crm system = ms excel) on Account and custom object. I would like to have in salesforce all the history I have on my external crm system (that I hope to don't use any more). So, on my external system I have all my account and the history of acc_custfield in the past. I have also all the record for my custom object withthe relation to the Account basing on the value of the acc_custfield. So for example I have the following data to upload:

Account A record with acc_custfield = XXX until a date and YYY after that date (I am not insterested to keep the date but only tracking history values)

Two Custom object records: one is related to Account A basing on acc_customfield = XXX (an history value because current account field value is YYY) and the other is related always to the Account A but basing on acc_customfield = YYY

I am uploading data using bulk api (the relation to the account is  based on the acc_customfield that is setas an external id field) but when I try to upload custom object records, all the records related to an history value of the Account are discarded.

how I can manage these cases?Is it possible to bulk uplaod values basing on history value of the Account custom field?

Best regards

[tlxforceteam]

Just to be more clear, I am importing using bulk api my data in csv file. To import my custom object and lookup the related Account, I have in my csv file the "Account__r.mycustomfield__c" value. This allow me to import custom object records and have mapped the relation to the Account. The problem is that the mycustomfield__c can change (i have changes in the history tracking) but I am not able to import custom object records that are related to old (history) value of the "Account__r.mycustomfield__c" field.

How can I manage this situation?Can I use history tracking or I have to create a new custom object to manage the mycustomfield__c changes?

Best Regards 

[tlxforceteam]

Any suggestion?

BR