C# , RSAC , pem file ,RSA

i need your help in  cryptography  .  i have keys wich were generated in openssl and  i need generete the key signature  loike ".pem. file  from another key  . which will encrypt my text . i don't want to get it in xml .  it is RSAC
for example  the result in xml is like that  .
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    <RSAKeyValue>
     <Modulus>xSFUXcDCAJJ3v3J87W7w92OuZ7JKuVv4Jpv0wkudbNKzd61HQPvbddq2dHWSxdjtbnqCbSiqnft5+BfuY4A81v4ZukIxwPza70jgGCb0dLToePteQdaUDxAoJToO5IqfkfeqinKuYKaGT35CrWzr27GQqWYc7QeuQkrJ6EHdJ3E=</Modulus>
      <Exponent>AQAB</Exponent>
      <P>4+Y3AWv5yta+Pe4VfDWAyZrBuY09ZZUAtqEu/DLvQF6F3DECh2JZM7eVff03Ffiw2TdYYvAnuuQicTCcMkVwPw==</P>
      <Q>3W/ee5qV12ayXLL1D/UCbWBQLEKp/vgicc9DtunVNT/5wdfMP1WZTW/csbiVmBKzc48olC9QFbZ8AzHEX698Tw==</Q>
      <DP>AL6Bs3l8yVLGMEGUxGEQWJguxcJWTvybkf0YwC4SZe1pFnz6eyKxE+Anls+63FGBklQB7+DE4HFaQ3BbMjbT1Q==</DP>
      <DQ>vBvBWy0Z5071a+wWZETVmAa+dKr48IDn+diBhIwls8OyLqpcdt0HixHg4BSW+AXC7gMKDMAYfylzNd98G3De3w==</DQ>
      <InverseQ>THgQutS7iiFQ0jDRroujpA5DfSfkQu8amv6bYD56zg61f4adm4zf6nTDOrut3i7GXxdKK+7PoRcbXdXmq6wO9Q==</InverseQ>
      <D>KT6f+D2sWZJLm7LIkKT1pc0lYGzdVYr4kJtwynYnqe0rv45xqhcIA9CO/C7dVqfchZD8WPp5ODS1gEMBja/3CmZ8SK04LEtZSHgMmTwZpH1Efpzz+9h/ujvxI1k4r521a7F1NV71YHZRMtyMfTlynYhpA6y1OyEa6tyhLLKRVEE=</D>
    </RSAKeyValue>  
    
    ---------------------------------------------------------------------------
    the file that i have is  
    ---------------------------------------------------------------------------
    -----BEGIN RSA PRIVATE KEY-----
    MIICXgIBAAKBgQDrM2IL88xRluJMeTKmWSI45MHvKhJszCEA4YCCeGp8GlAe5LGj
    pVr/4Zat2ARZSYX5J/LB8mwUJA81jCuEVDrW+uwnuH2Xg/Q+fzNCcc47I/E5GygU
    t4mqkbzjq5RtXN/ePfUUxAUV68SwW8BmRLZKXoxTBL/RLMK/ub1f1cclJQIDAQAB
    AoGBAKenzPAwLSjLoSxaCFzDlL1xczyEhPXA3JXAKNbX9y/Xod0jr+yy5hcYO0xY
    e2EaI8HjVAwkPh5tRdopvKtrTzSpPXFiO7xRG5suwscMn2BAzl2EIuAVXcajmy5c
    LJI7vNQeQzMA+D2xAuYFUv7jXtKVWWVIg2blcFifOsV+yrxRAkEA/sdRzjGOLDYW
    aaN18HaNtL5RXUEjc7rm6HUGLvxKHo1LN9O0sIr1oCOHlEVA+Salm+X/7CLc+gWd
    i9hF1OEcwwJBAOxUCUZagu02q17DQaAavGeOc3dRjv9i2omvOka4uBOP+N4nEUYd
    nEnI+ILHeAds4+NanxpoIXUueAp/elqXt/cCQGRtWvClFf6VX2ZKmY2snZT2RAo3
    R+sxbB2LK2HP7sN2PIUH/Txtuf5ioumuFrtfIX5/Pc7tux8OoZhjKruL9JMCQQCj
    +hdJYooPz+wOX4rMbWCmtfe2JbgDyfJ6sEPOSGMo56+1bQQWU3ta0wBjtcW52Tsy
    SHG23+O/LBQMrLEX5Me3AkEAvnLkZeoH36ZUMqsGinWe0FeN7rLl4CMSP3U1xy5i
    vvpKMzz0mceo4CWKJrwWfZuQQmxgjCdqEiWSzxfCGSDkew==
    -----END RSA PRIVATE KEY-----

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 please how i can slove this problem . anyone who can i need your soggestions .