Corporation Tax

We run a small Group of companies. The Parent is a non-trading holding company, which has 2 trading subsidiaries (both small companies, and 100% owned). Previously, the external accountants prepared the CT600 based on our Sage records. However, in the current cash constrained world, we are looking to it in-house for both subsidiaries, as they are pretty straight forward from a corp tax perspective. We cannot use the HMRC online facility as we are a group. I have looked at the Sage Corporation Tax product, but this seems to be designed for Practices rather than individual companies. We are not and will not be acting as an Agent. Are there any options within Sage to allow conversion of Accounts to XBRL format and then submission of the CT600 to HMRC (iXBRL).  Thanks.