change native Android SIP dialing settings My SIP Trunk (hooio) has a specific dialing plan: 

[Country Code][Phone Number incl. Area Code]


However, all mobile carriers have a different dialing plan: 

[Local Phone Number]   OR   
+[Country Code][Phone Number incl Area Code]


The main difference here being the 'plus'

All my phonebook entries are geared to work with the +[country][number] plan.
But when I dial these using the native SIP client, I get errors - since the trunk does not like the plus (!!! Should this not be a standard?!)

I'd really like to keep using this trunk, and they apparently cant or wont change their dialing plan.

Is there any way to configure rules for dialing with the native client? like remove the plus before dialing?   The only alternative is to have duplicate phonebooks for mobile vs internet calls - and I don't like my provider enough to waste time on this :(

Thanks anyone for advice or feedback on this! and Happy New Year!
I suppose "Prefixer" (written by "253°Below") or another app "PreFixer" can make the job of cutting the "+" symbols from the numbers' beginnings. However you will need to switch the Prefixer off to make the regular GSM calls. Else you can let the Prefixer do a smarter job by cutting pluses only from the numbers which look like "+123....." transforming them into "123.....".

Also there is an application which automatically transforms all the local(short) numbers in the address book into one standard by adding country codes and area codes. Its name is "Contacts Clean-up". It might do a portion of the required job, too.