The following code will open up Outlook Express and place e-mail address in proper box on pressing a button from Sesame layout form. "Email" is the name of an element that holds email address of a contact (You may change it to the name of your liking). You will have to place one command button on the layout form with the following code in the command button on Element Entry Event.

var Outlook_Exp_Path as string
var OutLook_failure as Int

Outlook_Exp_Path = @Chr(34) + "C:\Program Files\Outlook Express\msimn.exe" + @Chr(34)

IF Email <>"" THEN  
   OutLook_failure = @Shell(Outlook_Exp_Path + " " + "/mailurl:mailto:" + Email)  
IF NOT OutLook_failure = 0 THEN  
   @Msg("Couldn't open Outlook Express")  
// @Shell returns a 0 if it is successful, a 1 if it fails  

/* Email is the Name of the Element which stores e-mail address, you might have to replace that as per the name you have given for that element */

  

The credit of the above code goes to Bob Hansen as he has provided the essential element of the code.