Unable to convert String to a Number

Hello,

I have created a custom statement print, but I am having difficulty converting the line.charge string to a number for the values to be summed?

I can successfully remove the “£” and “,” characters i.e. £1,532.64 becomes 1532.64, but the ?number produces an error.

Without the ?number the string concatenates the values as it loops through the list.

<#if statement.lines?has_content>

<#assign linestblwsortcol = [] /> <!-- declare container for lines table with sort column -->

<#assign bal = 0 />

<#list statement.lines as tbl>

<#assign linestblwsortcol = linestblwsortcol + [tbl + {"sortcolumn":"${tbl.datecol?string('yyyy/MM/dd/')}${tbl.description}"}] /> <!-- add sort column to the lines table with value of joined Date and Description values-->