Xpath: Simple condition Check and assign value in Xpath Expression

I need do a check condition and if the condition not satisfies need to hard code the value. Below is my xml.

I need to check the condition like inside subroot- if ItemType=Table1 and ItemCondition=Chair1 then i have to give a hard coded value 'Proceed'( this hard coded value i will map to target side)

   <Root>
      <SubRoot>
          <ItemType>Table1</ItemType>
          <ItemCondition>Chair1</ItemCondition>
          <ItemValue>
              .......
           </ItemValue>
      </SubRoot>
      <SubRoot>
          <ItemType>Table2</ItemType>
           <ItemCondition>chair2</ItemCondition>
           <ItemValue>
               .......
           </ItemValue>
       </SubRoot>
   </Root>

I have tried like this but not seems to be working

      /Root/SubRoot[ItemType='Table1' and ItemCondition='Chair1']='Proceed'

Could you please anyone help on this. Thanks in advance.