Changing Characteristic format: Number of Chars

Hi Experts

I have created a characteristic, which is being used in a Variant class.

This characteristic is used to show selected product option prices (Currency format) in VC.

Format defined as 6 chars and 2 decimal places. (template is selected automatically)

It all worked fine, since the prices were under 10000 CHF...4 figures, eg. 9999.

But now the prices have changed and and gone up to 5 figures.. eg. 11000 which also need to appear in VC.

Since the characteristic is defined with 6 chars, when i try to add the new prices, i encounter an error:

Since there are Materials which have already been configured using this Characteristic.. i am not able to change the format.

Does anyone know what can be done in this case so that the characteristic allows 5 digit values?

Thanks & regards,

Shashank

P.S: I have already tried locking all the Dependencies and Variant tables  in which this characteristic has been used. But i still cannot change the format.