Has anyone gotten the SENDMESSAGE() aAPI call to work?

I need to send a text message to a VB 6.0 app from FPW2.6. I was hoping to use the SENDMESSAGE() API call, but I cannot get the correct syntax.

Basically I'm using the following code.

x=SENDMESSAGE(lnwindhand, wm_command, em_settext,lcmsg)

lnwindhand is the window handle of the app I'm sending the message to.
wm_command, I need the hex value of this
em_settext, I need the hex vcalue for this.
lcmsg = "1234568,Houston,Tx,Elm&Main"

Help please.