Excel export - different column width on different sheets

I am using jasperreports / ireport 4.7.

My report has a one-record-dummy-datasource and subreports in the detail section of the main report.

Each subreport output is on a new sheet. The columns in the subreports (jrxml) have the same width. That works fine.

But how is it possible to have different column width on different subreports/sheets without getting merged columns?

Is it possible at all?

Thanks.