Cost Re-Posting between Companies & add Company

Hi Experts,

I would like to ask you the following FICO questions -

Q1) After GR and/or IR for a PO item, value is posted to a GL A/C & Cost Ctr (or other cost objects) for the relavant company which is also responsible for Payment. However, we would like to re-post the value in the GL A/C & Cost Ctr (or other cost objects) from this company to another company's GL A/C & Cost Ctr (or other cost objects). As far as I know, using transaction FV50/FB50, KB61, KB11 or KB11N should be able to solve this, but seems GL A/C cannot be inputted in KB61, KB11 & KB11N. Therefore, which transaction is the most appropriate for this case ?

Q2) After the cost re-posting from one company to another, which standard report / transaction can be used to view the "variance in total amount" of GL A/C & Cost Ctr (or other cost objects) between these two companies ?

Q3) In our company, there is an existing Compay Code with "Country = HK" and "Currecy = "HKD". Currently, the SD business is for export sales (no tax is required). However, we will add a business for domestic sales in china and for some reasons a VAT Tax 17% (as a surcharge) will be included for each Sales Order finish good item. Currency in these Sales Orders will always be "RMB". If we also applied this business under this Company Code, could you advise whether there would be any impact on FICO module or whether it is appopriate to implement this ? or Should it be seperated by adding a new Compaby Code ?

Many Thanks,

KH Fong