this thread is for string
and i said with string i manage to do it but with child to customfields4all i dont know how to do the xml file import just an example below please edit that and tell me
<?xml version="1.0" encoding="UTF-8"?>
<export>
<product>
<sku><![CDATA[giannistest]]></sku>
<customname>Μπερές COUPE</customname>
<custom_param></custom_param>
<custom_title><![CDATA[Test Size-Color~Test Size-Color]]></custom_title>
<custom_value><![CDATA[stockablecustomfields~stockablecustomfields]]></custom_value>
<custom_multiple><![CDATA[]]></custom_multiple>
</product>
<product>
<sku><![CDATA[giannistest1]]></sku>
<customname>Μπερές COUPE 1</customname>
<parent_sku><![CDATA[giannistest]]></parent_sku>
<custom_param><![CDATA[One Size~BEIGE]]></custom_param>
<custom_title><![CDATA[testsizes~testcolors~]]></custom_title>
<custom_value><![CDATA[~]]></custom_value>
</product>
<product>
<sku><![CDATA[giannistest2]]></sku>
<customname>Μπερές COUPE 2</customname>
<parent_sku><![CDATA[giannistest]]></parent_sku>
<custom_param><![CDATA[One Size~Γκρι Ανοιχτό]]></custom_param>
<custom_title><![CDATA[testsizes~testcolors~]]></custom_title>
<custom_value><![CDATA[~]]></custom_value>
</product>
</export>