[TYPO3-english] mailformplus email_to (admin) problem

[G.Unger]

hi list

I have a problem with mailformplus and the correct typoscript for
plugin.tx_thmailformplus_pi1.default.email_to

In our case, we use a templavoila flexform construct (a contact person 
box) wich contains a little form and passes the email of the contact 
person to a mailformplus form.

I can get the mailformplus form then be sent to the admin like this:

plugin.tx_thmailformplus_pi1.default.email_to = TEXT
plugin.tx_thmailformplus_pi1.default.email_to.data = 
GPvar:contactperson_email_to

but the rquirements are to send the admin mail to 2 persons
a) GPvar:contactperson_email_to
b) a static 'backup-address' in case the contact person is on holiday or ill

I can fill out the values manually, this workz, and mail is send to 
both addresses
plugin.tx_thmailformplus_pi1.default.email_to = 
first.static at mail.com,second.static at mail.com

but I need the GPvar:contactperson_email_to plus a static address together.

I was looking for a CC/BCC function and tried some COA solutions, none 
with success.

anybody to put me on the right path?
thy and rgds,
GUIDO