If you are using Origin 7.0 or later the following OriginC function will do the job ...
 
bool wks_col_remove_char(string strWksName, int ColumnNumber, char Character)
{
	Worksheet Wks;
	if (Wks.Attach(strWksName))
	{
		Column WksCol;
		if(WksCol.Attach(Wks,ColumnNumber))
		{
			int NumRows=Wks.GetNumRows();
			string strCellValue;
			for(int i=0;i<NumRows;i++)
			{
				Wks.GetCell(i,ColumnNumber,strCellValue);
				strCellValue.Remove(Character);
				Wks.SetCell(i,ColumnNumber,strCellValue);
			}
			return (true);
		}
	}
	return (false);
}