Create file programmatically for import into Quicken?

I need to select some records from an SQL database and transform them into a Quicken-friendly format for the purpose of merging them into an existing Quicken 2012 Home and Business checking account.

Here's what I've done so far:

Attempted to import a QXF containing new transactions for a pre-existing account (named "Checking Account"). However, instead of importing the transactions into "Checking Account" it instead creates a new account "Checking Account 2" rather than importing/merging the new transactions into the appropriate pre-existing "Checking Account" account. According to Quicken's site (link at the bottom of the page) this is what's happening:

When importing a QXF file, it's possible that one or more accounts in the QXF file already exist in the destination data file. If this is the case, Quicken will not attempt to merge the transactions in these duplicate accounts. Instead, Quicken will create a new account

Contacted Quicken, however their support was clearly having trouble understanding the question and they only knew how to use the program and could not provide any additional information on which format to use.
Researched QFX, QXF, OFX and QIF

From what I've read OFX is not supported (instead QFX is used for financial institutions registered with Quicken only). Additionally QIF is being phased out and does not support the Checking account I need to import these records into. Finally, QXF has proven difficult to locate information on but from what I've read it is an encoded file format that requires some SDK to create and aside from this issue (as stated above) it does not import according to my criteria.

I'm at my wits end here and I've spent several hours researching the topic. Any help would be appreciated.

UPDATE: Please understand I'm not asking for your "favorite" SDK, I'm simply having troubles discovering what my options are and I would appreciate the StackOverflow community point me in the right direction.

References

Quicken QXF Literature: http://quicken.intuit.com/support/help/backup--restore--file-issues/importing-and-exporting-qxf-files-in-quicken-essentials-for-mac/GEN83152.html

Solution

After extensive research, I found the solution to be QIF. Though Quicken states:

Note: QIF import is not available for checking, credit card, savings, 401(k), or any other brokerage accounts.

This appears to be a mis-statement as it's really only enforced when Exporting data. After adding the following four lines (documented [here][1]) to the top of any QIF, I have successfully imported/merged new transactions into an existing Quicken 2012 Checking account. My understanding is this will work for any account, regardless of the type.

!Account
NJoint Brokerage Account
TInvst
^

In my situation I only needed to replace "Joint Brokerage Account" with the account name I wished to import into, even though the type specified is "Invst" and my account is "Checking", this still succeeded.

Quicken QIF Literature: Importing Data Into Quicken (Updated: 4/27/2012 | Article ID: GEN82389) Solution URL: Direct Method