Try,
D2, Enter the Country name.
Copy down the formula.
If the lookup country is not in the current row, will show as 0.
Format the cell to percentage.
Excel 2007<table style="background-color: rgb(255, 255, 255); border: 1px solid rgb(166, 170, 182); border-collapse: collapse;" cellpadding="2.5px" rules="all"><colgroup><col style="background-color: rgb(224, 224, 240);" width="25px"><col><col><col><col></colgroup><thead><tr style="background-color: rgb(224, 224, 240); text-align: center; color: rgb(22, 17, 32);"><th>
</th><th>A</th><th>B</th><th>C</th><th>D</th></tr></thead><tbody><tr><td style="color: rgb(22, 17, 32); text-align: center;">1</td><td style="text-align: right;">3.1%</td><td style="">Brazil: 9.1%France: 8.2%Mexico: 3.1%</td><td style="text-align: right;">
</td><td style="font-weight: bold;">Lookup Country</td></tr><tr><td style="color: rgb(22, 17, 32); text-align: center;">2</td><td style="text-align: right;">13.3%</td><td style="">Italy: 25.6%Mexico: 13.3%Brazil: 12.5%India: 4.5%</td><td style="text-align: right;">
</td><td style="text-align: center;">Mexico</td></tr></tbody></table>
Sheet1
<table style="border: 2px solid black; border-collapse: collapse; padding: 0.4em; background-color: rgb(255, 255, 255);" width="85%" cellpadding="2.5px" rules="all"><tbody><tr><td style="padding: 6px;">
Worksheet Formulas<table style="border: 1px solid rgb(166, 170, 182); text-align: center; background-color: rgb(255, 255, 255); border-collapse: collapse;" width="100%" cellpadding="2.5px" rules="all"><thead><tr style="background-color: rgb(224, 224, 240); color: rgb(22, 17, 32);"><th width="10px">Cell</th><th style="text-align: left; padding-left: 5px;">Formula</th></tr></thead><tbody><tr><th style="background-color: rgb(224, 224, 240); color: rgb(22, 17, 32);" width="10px">A1</th><td style="text-align: left;">=LOOKUP(
1E+100,CHOOSE({1,2},0,LOOKUP(1E+100,--LEFT(REPLACE(B1,1,SEARCH($D$2,B1)+LEN($D$2),""),{1,2,3,4,5,6}))))</td></tr></tbody></table></td></tr></tbody></table>