Number Range Problem in MDM

Hi ,

We are using external number range.We have maintained number ranges for 3 vendor account groups in console(Remote Systems).But now in R/3 some Vendors have been created in that specific number range.So there is a need to change the number range so that the new vendor number that is generated by MDM comes after the vendor number that is present in R/3.So I changed the number range accordingly but it is not reflected in the system.It still generates the previous vendor number.So is there a way to overcome this ?

Thanks,

Ram