HMR help, removing one parameter from the FROM header

I need to remove the otg parameter before sending out and invite and I'm having trouble getting the HMR correct.  Wondering if someone can help.

 

From: "normal_call" <sip:8648844949@10.105.201.7:5060;otg=TEST>;tag=SDspdo202-1

 

I need to remove the ;otg=TEST and it is a text field that can be however how long and with whatever characters.  It should look like:

 

From: "normal_call" <sip:8648844949@10.105.201.7:5060>;tag=SDspdo202-1

 

Going out.  Any help is appreciated.

 

 

Here is what I took a stab with and it isn't working...

 

sip-manipulation
        name                           Remove_OTG
        description                    Invite"
        split-headers                 
        join-headers                  
        header-rule
                name                           remove_otg
                header-name                    from