CRM - Send Mail - From Mail Merge.

Hello Guys,

We are using this custom code to send mails from CRM environment for our custom entities (invoked from workflow activity code).

TargetSendFromTemplateEmail myTargetSendFromTemplateEmail = new TargetSendFromTemplateEmail();
myTargetSendFromTemplateEmail.Email = myEmail;
SendEmailFromTemplateRequest mySendEmailFromTmpRequest = new SendEmailFromTemplateRequest();
mySendEmailFromTmpRequest.Target = myTargetSendFromTemplateEmail;
mySendEmailFromTmpRequest.RegardingId = guidRegardingObjectid;
mySendEmailFromTmpRequest.RegardingType = "new_course";

-- IMPORTANT -- 
mySendEmailFromTmpRequest.TemplateId = guidMailMergeid;

-- IMPORTANT --
but mySendEmailFromTmpRequest.TemplateId just accepts mail tamplate and not MAIL MERGE template which just works for custom entitites.

Any ideas how to accomplish it on this or another way, for instance getting data saved on DB, as far as we can see it is encrypted :(:(?

Regards
Alex